NationalOpticalAstronomyObservatories

NATIONAL OPTICAL ASTRONOMY OBSERVATORIES

LONG RANGE PLAN

FY 1993 - FY 1997

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March 17,1992

NationalOpticalAstronomyObservatories PP. Box 26732 Tucson, AZ 85726-6732

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TABLE OF CONTENTS

EXECUTIVE SUMMARY 1

I. INTRODUCTION AND PLAN OVERVIEW 4

II. NIGHTTIME ASTRONOMY 6

A. Science at CTIO and KPNO 6

1. The Large-Scale Structure of the Universe 62. The Formation and Evolution of Galaxies 7

3. Stellar Structure and Evolution 10

4. Star-Formation 11

B. Initiatives for CTIO and KPNO 12

1. Gemini 12

2. WIYN 14

3. 4-m Telescopes at CTIO 154. The 2 um All Sky Survey (2MASS) 165. Beyond 8-m Telescopes 17

C. Instrumentation for CTIO and KPNO 17

1. Cerro Tololo Inter-American Observatory 192. Kitt Peak National Observatory 25

a. KPNO Infrared 26

b. KPNO Optical-Ultraviolet (O/UV) 31c. 3.5-m Mirror Project 33

in. SOLAR ASTRONOMY 34

A. Science at NSO 34

1. Internal Dynamics 342. Magneto-Convection 35

B. Initiatives for NSO 39

1. Global Oscillation Network Group (GONG) Project 392. Large Earth-based Solar Telescope (LEST) 423. Upgrade of the McMath Teleseope to a 4-m Aperture "The Big Mc" 434. Advanced Reflecting Coronagraph (ARC) 44

C. Instrumentation for NSO 46

IV. OBSERVATORY OPERATIONS 55

A. Cerro Tololo Inter-American Observatory 55B. Kitt Peak National Observatory 58C. National Solar Observatory 60

V. NOAO OPERATIONS 64

A. Scientific Staff 64B. Computer Support 64C. Facilities Maintenance 73

VI. BUDGET 79

Index of Tables

Table 1 - CTIO Five-Year Instrumentation Plan Summary 19

Table 2 - KPNO IR Five-Year Instrumentation Plan Summary 25

Table 3 - KPNO O/UV Five-Year Instrumentation Plan Summary 30

Table 4 - NSO Five-Year Instrumentation Plan Summary 46

Table 5 - CTIO Telescope/Instrument Combinations 56

Table 6 - KPNO Telescope/Instrument Combinations 59

Table 7 - NSO Telescope/Instrument Combinations 63

Table 8 - NOAO/Tucson Schedule of Major Capital Expenditures 65

Table 9 - KPNO Schedule of Major Capital Expenditures 65

Table 10 - CTIO Schedule of Major Capital Expenditures 67

Table 11 - NSO Schedule of Major Capital Expenditures 67

Table 12 - NSO/T and NSO/KP Schedule of Major Capital Expenditures 68

Table 13 - Maintenance Requirements 74

EXECUTIVE SUMMARY

The mission of NOAO, according to a letter sent to the NSF by AURA in May 1988, is "to conductworld-class scientific investigations in exploring the universe at optical and infrared wavelengths. Thisincludes building, operating, and conducting research with world-class facilities of a range of sizes andtechnical capabilities open to all US astronomers; and coordinating, participating in, and often leading thetechnology development programs essential to all optical/infrared efforts in the US."

This mission statement translates into specific objectives for the observatory, many of which weresummarized in the five-year renewal proposal, which was submitted to the NSF four years ago. Theseobjectives include excelling in service to the community, in building and operating facilities andinstrumentation, and in scientific research by the staff; working for the best interests of US astronomy byco-operating with, and complementing the capabilities and interests of, the US university communitythrough joint programs and projects; completing and operating the GONG facilities; representing the USinterests in the Gemini program to construct modem 8-m telescopes in both hemispheres; and modernizingthe facilities at existing sites, both by upgrading the telescopes already in operation and by participatingin joint projects with universities to build modern 4-m class telescopes.

In translating these objectives into specific programs, we have defined the future role of NOAO to bebroader than its traditional task of providing telescopes to those who do not have access to their own. Wesee NOAO as having a responsibility for enabling science not only through the telescopes it provides butalso by disseminating both data and technology throughout the groundbased community. We plan to carryout this responsibility by:

• Operating telescopes with a variety of instrumentation and a range of apertures so that the UScommunity continues to have open access to world class facilities.

• Making our sites available for facilities and projects carried out by university and other groups, withshared infrastructure leading to efficient and low cost operations for all of the participating groups.

• Entering into agreements with universities to provide observing time in return for making university-built instrumentation available to the user community.

• Assuming the responsibility on behalf of, and in partnership with, the community for executing majorprograms, with GONG and RISE (Radiative Inputs from the Sun to the Earth) being two examples.

• Participating with universities in joint construction of 4-m class telescopes, one in the north and onein the south, thereby obtaining more observing time for the community, providing technical expertiseto assist with construction and operation these telescopes, and assisting the participating universitieswith strengthening their instrumentation, graduate education, and research programs.

• Becoming a focal point for the acquisition, characterization,optimization, and distribution of detectors.The combination of Gemini funding plus NOAO expertise provides an opportunity to negotiateeffectively with manufacturers to optimize detectors for groundbased astronomy. It is NOAO'sintention to compete to play this role for Gemini and to facilitate distribution of detectors andoperating information to the partner countries and to instrument groups in the US.

• Disseminating information on technology and instrumentation that is developed both by NOAO andthe Gemini staff, including working more closely with other large telescope projects in the US.

• Using the existing telescopes, both solar and nighttime, to test new instrumentation, including adaptiveoptics, to try out innovative observing techniques, and to experiment with flexible schedulingalgorithms.

• Making data products available to a broader segment of the community through archiving, initiallyof large data sets reduced to a uniform and common standard. Examples are the GONG data and mapsof star-forming regions in the infrared.

• Work with the community to define and carry out programs requiring commitments of large amountsof observing time. Such programs might include asteroseismology, deep imaging of galaxies, andredshift surveys of selected classes of objects, but the specific programs will be selected after reviewof proposals submitted by the community and NOAO staff.

During the construction phase of both the Gemini and LEST projects, we expect NOAO to be the focalpoint for input from the US community into defining the scientific requirements for the new telescopes,for making sure that the US community participates in design reviews and in recommending priorities asbudget constraints become defined, and for ensuring that the US community, including NOAO, submitsstrong proposals to build an appropriate share of the instrumentation required for these facilities.

Since the US is the major partner in Gemini, we believe that the headquarters for the project should bein Tucson. While the purely administrative and scientific staff associated with the headquarters should bekept to a minimum, there should be sufficient technical resources available to the project to overseecontracts for fabrication of instrumentation, for upgrading the performance of the telescopes, and forcontinuing development of software, with the goal of maintaining a common set of standards andinterfaces for both Gemini telescopes. The Gemini project should be able to share Tucson personnel withKPNO and NSO, so that it can have access to the range of expertise needed by the project, but with fullcosts for the staff used by Gemini paid for by the Gemini project.

Beyond the projects currently underway, NSO is examining a variety of options, including constructionof an All-Reflecting Coronagraph (the ARC) and upgrading the McMath to a 4-m equivalent telescope.The Big Mc would provide a unique facility for infrared solar astronomy and for solar-stellar observations.

On the nighttime side, it is our judgment that the next major facility for groundbased optical/infraredastronomy will be an array of telescopes for interferometry. Many technical issues must be resolved beforeit is possible to define the optimum combination of number of telescopes, aperture of individualtelescopes, and baselines over which they should operate. We believe it is best that the variety ofdevelopments needed to specify a national interferometric facility be carried out by the numerousinterested university groups. NOAO can participate in some of these projects, provide sites for one or moreof them, support and facilitate communication among the groups, and aid in planning the national facility.Some of the 8-m telescope engineers have the capability of designing such a facility and preparing aproposal for funding, and they will complete the Gemini telescopes at the end of this decade, which shouldbe about the time the major technical issues involved in defining the national interferometric facility havebeen resolved.

Over the past five years, NOAO has developed and made available to the community several instrumentsthat greatly exceed in complexity what was previously available. Examples include fiber positioners plusspectrographs at both CTIO and KPNO, the four-color infrared imager (SQIID) at KPNO, and the near-infrared magnetograph (NIM) at NSO. There are plans during the next five years to build a mosaic ofCCDs for wide-field imaging; a high resolution infrared spectrometer, adaptive optics for solar astronomy;tip-tilt mirrors for optical and infrared imaging; and new electronics and controllers to handle high datarates in both the infrared and optical.

Key milestones for the next five years are as follows:

FY 1993

October 1992

October 1992

October 1992

November 1992

December 1992

March 1993

April 1993July 1993August 1993September 1993September 1993September 1993

FY 1994

December 1993

February 1994March 1994

March 1994

June 1994

July 1994August 1994

FY 1995

October 1994

December 1994

January 1995March 1995

August 1995September 1995

FY 1996

October 1995

April 1996August 1996

NOAO Milestones (FY 1993 - FY 1997)

GONG system design reviewGONG data reduction and analysis hardware orderedInitial telescope test of cryogenic optical bench at KPNOPreliminary design review period for major 8-m telescope partsTelescope tests of HgCdTe IR camera at KPNOCompletion of WIYN telescope enclosureInstallation of WIYN telescope mountGONG data reduction and analysis hardware operationalInitial telescope test of CCD mosaic prototype (2 x 2) at CTIOGONG deployment readiness reviewInitial telescope test of image stabilization camera at CTIOCompletion of all major critical design reviews for the 8-m project

GONG network deployment beginsFirst light for WIYN telescopeDelivery of first 8-m primary mirror blankInitial telescope test of PHOENTX at KPNOGONG network operations beginNSO adaptive optics system operationalInitial telescope test of second generation infrared spectrometer at CTIO

LEST construction initiated

Initial telescope test of CCD mosaic (4 x 4) at KPNOFull scientific operation of the WIYN telescopeAssembly of the 8-m enclosure at Mauna Kea beginsInitial telescope test of the new 4-m f/7.8 secondary at CTIOInitial telescope test of the CCD mosaic (4 x 4) at CTIO

4-m McMath Upgrade start or Large All-Reflecting Coronograph startInitial telescope test of JHKL spectrometer (GrASp) at KPNOInitial telescope test of 10-ujn camera at CTIO

FY 1997

November 1996 Start of factory assembly and test of first 8-m telescope mountJune 1997 GONG observations end

September 1997 LEST first light

All of this is what could and should be achieved by the national observatories. These tasks could all befit within the funding envelope recommended as its highest priority by the Astronomy and AstrophysicsSurvey Committee.

The reality of the situation, however, is that NOAO is the only segment of the NSF astronomy programthat is planning for budget cuts in FY 1993. At a time when the overall NSF budget request is up bynearly 18 percent and the astronomy budget up by 6.9 percent, the request for NOAO is up by only 3.5percent. There is no recognition of the ongoing problems caused by the steady deterioration of the dollarrelative to the Chilean peso. In order to increase GONG funding as scheduled, compensate for Chileaninflation, and maintain current services, NOAO requires S800K more than was included in the President'srequest.

All studies of NOAO programs, whether they dealt with safety or telescope operations, instrumentationor personnel, user services or inventory control, have recommended increases in staff to support thecurrent workload. Staffing problems are aggravated by the advent of Gemini, which requires substantialsupport from NOAO scientific staff for whom, by international agreement, it does not pay. Gemini fundsare not under the control of the NOAO director and cannot be used to relieve NOAO's budget problems.We can no longer devise ways to do the same job with diminished resources.

In FY 1993, the funding at the level of the President's budget for non-payroll items required by theinstrumentation program will fall a factor of two short of what is required by the plan presented here. Ifthis budget level is not increased, it will be impossible to continue full time operation of all of the existingtelescopes, and the advent of WIYN will surely force closures on Kitt Peak. NOAO will have to giveserious consideration to withdrawing from participation in the SOAR telescope, which is a 4-m telescopedestined for Cerro Pachon. The modest upgrades planned for the existing 4-m telescopes will be multi-yearprojects, and upgrades to the McMath will be deferred indefinitely. State-of the art instrumentation willcontinue to be equipped with detectors that are behind the state-of-the-art in sensitivity or area or both bya factor of ten or more. The budget for the 8-m telescopes is now being stretched out, as were the budgetsfor the GONG and VLBA projects.

Because we have not decided where to make the cutbacks required in FY 1993, we show in the programplan what we would do if the funding were at a level to accomplish the programs we have outlined. Wethen show as a deficit the difference between that amount and the amount actually requested in thePresident's budget.

I. INTRODUCTION AND PLAN OVERVIEW

More than three decades have passed since the founding of AURA, and this has been a remarkable periodin astronomy. Quasars, pulsars, and the cosmic background radiation were all discovered since 1960.Access to space has led to the opening of the gamma-ray and X-ray windows. Infrared astronomy, firston the ground and then in space with the IRAS satellite, has revolutionized our view of star-formation,

of the structure of the interstellar medium, and of the energetics of active galaxies. Radio telescopes havediscovered and mapped molecular clouds and explored the nuclear structure of active galaxies and quasars.There have been voyages of discovery to the planets and to comet Halley. With the measurements of solarneutrinos and oscillations, astronomers have developed diagnostic tools that allow them to probe theinterior structure of the Sun.

The Hubble Space Telescope has already been launched, and during the next decade and a half we canexpect to have long-lived space observatories for gamma-ray, X-ray, infrared, and solar astronomy. Thesefacilities, combined with immensely more powerful ground-based telescopes, will provide the toolsnecessary to resolve, or at least to begin to resolve, the fundamental questions raised by the manydiscoveries during the past thirty years. What is the large-scale distribution of matter in the Universe? Towhat extent does luminous material trace the distribution of mass? Did galaxies all form at about the sametime, or are there young galaxies relatively nearby? Once formed, do galaxies evolve at a uniform rate,or does the pace of evolution depend on local conditions? What is the nature of the engine that powersthe emission from quasars and active galaxies? What triggers star-formation? What determines the initialmass function, the frequency of binary and multiple systems, and the conditions under which planetarysystems result? How well do models represent the detailed structure of the Sun? Can we use solaroscillations to probe the subsurface structure of solar activity? What are the causes of chromosphericheating? Can we devise successful models of the magneto-hydrodynamics and plasma processes thatgovern the storage and release of energy in active regions and flares?

Ground-based observations will continue to play a central role in answering these fundamental questions.The high density of spectral information in the optical and infrared regions of the spectrum makes theseoften the wavelengths of choice for analyzing the dynamics, physical conditions, and compositions ofastronomical objects.

The opportunities now available in astronomy have not been matched at any time in the history of thefield. Advances in observing techniques and the feasibility of building much larger telescopes with muchbetter image quality for both solar and nighttime astronomy are stimulating innovative thinking andattracting some of the most talented scientists of our generation. New regimes of high spatial resolutionand new precision in spectroscopy can be attained. It has become possible to attack qualitatively new kindsof problems ranging from the interior structure of the Sun and stars to the formation and evolution of largescale structures.

NOAO has developed a plan that would permit it to meet the needs of the observing community for newcapabilities and for upgrading existing facilities, and this document describes that plan. In order to makeit easier to follow the programs for solar and nighttime astronomy in their entirety, plans for each arepresented separately. For each of these two areas of NOAO activities, we outline first some of the keyscientific opportunities for the next several years. It is this analysis that forms the basis for the specificplan presented in this document. The succeeding sections describe the initiatives in each area--4-mtelescopes for the nighttime program, LEST and stellar synoptic studies within NSO. The plan thendescribes the status of ongoing initiatives-work on borosilicate glass mirrors and GONG. The followingportions of the plan describe the observatory operations within each of the divisions of NOAO anddescribe how the instrumentation at each site will evolve. The subsequent sections discuss programsrelevant to NOAO as a whole, including issues relating to the scientific staff, to development of computingand archiving capabilities, and to maintenance of facilities. The final section of the plan presents thebudget required to carry out the proposed programs.

II. NIGHTTIME ASTRONOMY

A. Science at CTIO AND KPNO

The scope of the research supported by NOAO is extremely broad. Approximately 10.000 scientific paperswere published between 1961 and 1991 by NOAO staff and by visitors who made use of NOAO facilities.In this plan, we summarize key results in a few particularly active areas of research and indicate wherewe think the promise of rapid progress is the greatest. It is, of course, this assessment of the future courseof our science that has determined our priorities for new instrumentation and for major initiatives.

1. The Large-Scale Structure of the Universe

The earliest cosmologies began with the assumption that the Universe is homogeneous and isotropic. Thisassumption has persisted until the present. Current theories posit homogeneity and isotropy when averagesare taken over a large enough scale. In recent years, however, observations taken with telescopes operatedby NOAO, as well as other institutions, have begun to pose serious challenges to these assumptions andto current cosmological models.

In 1983, R. Kirshner (Center for Astrophysics) and his collaborators used the KPNO telescopes to identifywhat appeared to be a gigantic void in the direction of the constellation BoOtes. In 1986, this same groupused the KPNO facilities to confirm the existence of this void, which occupies a volume of over onemillion cubic megaparsecs and is roughly spherical in shape with a diameter of about 120 Mpc. Also in1986, V. de Lapparent, M. Geller, and J. Huchra (Center for Astrophysics) published results from theextended Center for Astrophysics redshift survey, which showed galaxies residing on the surfaces ofcontiguous bubble-like structures whose diameters are typically 25 Mpc with a maximum of 50 Mpc. Asimilar picture of the distribution of galaxies in space emerged from a 21-cm survey of 2,700 galaxiespublished in 1986 by M. Haynes (Cornell U.) and R. Giovanelli (Arecibo Obs.). More recently, a groupof seven investigators (D. Lynden-Bell, S. Faber, D. Burstein, R. Davies, A. Dressier, R. Terlevich, andG. Wegner) have used KPNO and other telescopes to discover streaming motions of galaxies on anextremely large-scale. Their analysis of the motion of 400 elliptical galaxies has revealed a net streamingmotion of galaxies over a region about 100 Mpc in size, with a velocity at the Sun of roughly 570 km/sover and above the uniform Hubble flow. The existence of a "Great Attractor" is still a matter of

controversy at present if it does exist, it may have a mass ofabout 5 x 1016 solar masses. Its center islocated in the direction of the constellation Centaurus.

A startling new result has emerged from the work of D. Koo (Lick Obs.) and his collaborators on thelarge-scale distributionof galaxies. Using pencil beam surveys of the north and south Galactic poles, theseinvestigators have sampled the distribution of galaxies over an unprecedented scale of 2000 Mpc, whichis far deeper than any previous surveys. They find well-ordered large-scale features in the galaxydistribution out to the limits of the survey. In addition there is a tantalizing hint of periodicity in thisstructure at an interval of about 130 Mpc. Work is continuing on this project using telescopes at CTIOand KPNO. If confirmed, it will provide evidence for structure on the longest scale yet discovered.

All of these large-scale features in the galaxy population pose severe challenges to current cosmologicalmodels. The difficulties lie in the inability of the models to produce such large structures by purelygravitational means. The hot dark matter models use the hot particles to suppress excessive small-scalefluctuations, but in conventional cosmologies with Q, = 1 they do not reproduce the galaxy-galaxy

correlation function, and they have difficulty producing the giant mass fluctuations required to explain thelarge-scale streaming motions. Cold dark matter models cannot produce the large structures, and they yieldtoo much small-scale structure unless ad hoc assumptions such as biased galaxy formation are introduced.Non-gravitational theories using shock waves to initiate galaxy formation may successfully account forthe observed structure, but they require as yet unobserved explosive events of enormous energy, about1065 ergs per event, which is equivalent to the energy radiated by 10,000 galaxies over the age of theUniverse.

The dilemma faced by current theories has caused some consternation, particularly because thegravitational models have appealing features from the standpoint of high energy particle physics. It is clearthat the continuing and widespread interest in cosmology and its implications for the large-scale structureof the Universe will motivate many programs in observational astronomy during the next five years.Further work is required to determine just how empty the voids really are, and it is also necessary tosearch for any gaseous intergalactic matter in the voids. How common is the large-scale streaming motion?Is the suspected periodic nature seen in the pencil beam surveys real? Additional and more distant surveysneed to be carried out. One is currently being planned that uses rich Abell clusters of galaxies. Thepossibility of using another velocity independent distance indicator in the infrared is also being explored.

A crucial element in cosmological models is the evolution of structure with time, and because galaxiesare too faint to be detected at the relevant look-back times, surveys of quasar distributions are of greatimportance. Confirmation of these large-scale structures and a determination of their evolution in time willnot only constrain cosmological models but will also lend insight into the effects of possible non-baryonicor "dark" matter components in the Universe. Moreover, detection of non-random features in the initialperturbation spectrum could indicate the presence of cosmic strings. Addressing these issues requires alarge database, which must be acquired in a systematic and self-consistent manner. The new telescopesand instruments planned for use at NOAO will be an essential component in the success of these typesof programs. The planned construction of a 3.5-m telescope on Kitt Peak, in cooperation with universitypartners, will allow long-term, dedicated programs to be carried out One candidate program is a massiveredshift survey, which will supply detailed dynamical data over a sample large enough to address theseproblems. Further into the future, the large collecting area of 8-m telescopes, when coupled with the speedof fiber-fed multi-object spectrometers, will result in an improvement of more than two orders ofmagnitude over current facilities. This capability will allow the analysis of faint quasars and clusters ofgalaxies at redshifts between one and three, which is an essential period in the study of the evolution oflarge-scale structure.

2. The Formation and Evolution of Galaxies

The simplest view of galaxy formation assumes that there was some epoch when galaxies formed theirconstituent stars, with all subsequent evolutionary effects resulting from the relatively slow and continuousprocess of stellar aging in combination with smoothly declining rates of star formation. Until quite recentlythis view was the prevalent one. Observations taken over the past several years, particularly at KPNO andCTIO, have shown the need to modify this view. It is important to note that many of these observationssimply could not have been made without the current generation of sophisticated solid state detectors andtheir accompanying instrumentation.

One of the first indications of a more complex picture was revealed ten years ago when H. Butcher(Kapteyn Obs.) and G. Oemler (Yale U.), using the KPNO telescopes, discovered that rich clusters of

galaxies appear blueras theirdistance increases. In an observing program spanning several years, Butcherand Oemlerdiscovered that nearby rich clusters tend to be populatedwith old, quiescent elliptical galaxies,yet these observations suggested that at earlier epochs such galaxies were undergoing significant amountsof star-formation. The clusters surveyed extended out to a redshift of approximately 0.4, whichcorresponds to looking backapproximately one quarter of the age of the Universe. This result, which hassince been confirmed, indicates a much more rapid evolution of elliptical galaxies in clusters than hadbeen previously thought. A second set of relevant observations comes from a survey of the galaxiesassociated with strong radio sources. H. Spinrad (U. of California, Berkeley) and S. Djorgovski (Centerfor Astrophysics), using the KPNO telescopes, have obtained data on some of the most distant galaxiesobserved. Looking back to times half the age of the Universe or less, they find that these radio galaxiescontain a great deal of hot, ionized gas which is in very rapid, turbulent motion. The galaxies themselvesoften appear distorted or moderately disrupted. This work has been confirmed and expanded byP. McCarthy (Mt. Wilson), who has found this effect in a larger, more complete sample of radio galaxiesvia observations with the KPNO 4-m telescope. Recently McCarthy and his colleagues have discovereda giant (100 x 170 Kpc) cloud of ionized gas surrounding the radio-galaxy 3C 294. This cloud is verymassive (about 109 Mo) and seen at a redshift of 1.79; its kinetic energy alone may be as large as 1059ergs. This cloud may be the remnant of the protogalactic nebula from which 3C 294 was formed. By wayof contrast, similar strong radio sources nearby (redshifts < 0.1) are found to be associated with oldelliptical galaxies which containvery little gas and are regularandundisturbed in appearance. Hence, thereis strong evidence for major changes with time for this special class of galaxy.

Further evidence for evolution was found by A. Tyson (Bell Labs.) in examining the environment ofquasars at two different epochs. The CTIO and KPNO telescopes were used to observe quasars in theredshift ranges 0.1 - 0.5 and 1.0 ~ 1.5. Tyson found that the more distant quasars had ten times moregalaxies around them than did the nearby sample, indicating a drastic change in luminosity for thesegalaxies with time. Another, unbiased, sample was obtained by Tyson and P. Seitzer (CTIO) with deepCCD imaging. This survey found that galaxies at half the age of the Universe are consistently bluer andthus have much more active star-formation than at the current epoch. Another striking case has been therecent discovery of a very large (100 kpc) cloud of ionized gas at a redshift of 1.82, which looks back totwo-thirds the age of the Universe. No stellar population is found, though a radio source is present. Thedata are consistent with this beinga galaxy in the process of formation. A final complication emerges fromthe work of D. Hamilton (CTIO, now at California Inst, of Technology), which shows the existence ofa very old, unevolving population of red galaxies, which have basically been unchanged for about halfthe age of the Universe. In addition, S. Lilly (U. of Toronto) has shown that the rapidly evolving radiogalaxies at large redshift may also have an underlying stellarpopulation that is very old, consistent withan epoch of formation at a redshift of about five. This picture has been made more complex by recentresults from the KPNO two-dimensional infrared array. These K-band data indicate that the old stellarpopulation in these galaxies may be elongated along the axis of the radio source. This now seems to bea general feature of these distant radio galaxies, and thus implies that models for star formation in themneed to be revised. A furthercomplication has arisen from data obtained in recent months using this arraycoupled with a polarimeter. In a small number of radio galaxies, theelongated emission shows significantpolarization. This may imply that a large amount of the light is actually scattered emission coming fromthe nucleus and not from stars. Just how much of the emission can arise in this manner is not yet clear,nor is the frequency of occurrence of polarization of the light in these objects. This important area ofinvestigation will evolve rapidly in the next few years.

Thus, recent observations suggest that galaxy formation was far from coeval, that galaxies may have beenforming throughout the age of the Universe, and that many, but not all, have undergone dramatic

evolutionary changes in that time. The possible nature of these evolutionary forces is also becomingclearer through recent work at NOAO and elsewhere. In many cases, those galaxies that show strongevidence for evolution are found to be in special circumstances: in clusters of galaxies, near quasi-stellarobjects, or associated with strong radio sources. Membership in a cluster of galaxies provides severalmechanisms that can perturb a galaxy and thus change the history of its star-formation. Near encounterswith other galaxies, stripping of gas by ram pressure of the intergalactic medium, or conversely, accretionof such gas by cooling flows onto a massive central galaxy are all possibilities. It is by no means clearwhich of these processes is relevant, and much further work needs to be done. That the proximity ofquasars to galaxies may be important was implied by the survey of Tyson. In addition, R. Green (KPNO)and H. Yee (U. de Montreal) have used the facilities at NOAO and the Canada-France-Hawaii Telescopeto show that the clusters of galaxies associated with quasars become much richer beyond a redshift ofabout 0.5. The exact nature of this interaction is again unclear, but not the reality of the effect.T. Heckman (U. of Maryland) and his collaborators have used NOAO telescopes to determine that galaxiesassociated with radio sources often reside in regions of higher galaxy density than do similar galaxies thatare "radio quiet." This trend becomes more apparent with increasing redshift, as has been recentlydiscovered by S. Lilly (U. of Toronto). In addition, Heckman, Miley (STScI), van Breugel (U. ofCalifornia, Berkeley), and their collaborators have established, in a multi-year program, that many radiogalaxies have copious amounts of hot ionized gas enriched with heavy elements and spread throughoutand beyond the galaxy. Such galaxies often show a distorted morphology. Again, this body of dataindirectly suggests the presence of some form of interaction among galaxies.

It may be that encounters with other galaxies are a condition for rapid and dramatic evolution of galaxies.However, the deep CCD survey of Tyson and Seitzer implies that many isolated galaxies also haveundergone significant evolution. A particularly elusive indication of galaxy formation and evolution comesfrom the "forest" of Lyman-oc absorption lines seen against distant quasars. These systems have beenobserved at NOAO by D. York (U. of Chicago) and by Green and J. Bechtold (U. of Arizona), but theirexact nature remains in doubt A possibility is that these systems are primordial or protogalaxies lyingalong the line of sight to the quasar. However, a better definition of their properties is needed to allowresolution of this question. Another group of galaxies that may be undergoing dramatic evolution are thoserecently detected by the Infrared Astronomy Satellite (IRAS) satellite. These objects emit up to 10 timesthe luminosity of a normal spiral galaxy, with the emission mostly in the far-infrared region. The presenceof copious amounts of dust is suspected, but many more observations will be required to define theseobjects properly. An alternative candidate for a galaxy in the earliest stages of evolution is the hydrogencloud discovered by Giovanelli (Nat. Astronomy and Ionosphere Center) and Haynes (Cornell U.). Thiselongated cloud seems to offer support for the idea that disks of galaxies can form slowly throughout thehistory of the Universe.

Although a wealth of data apparently exists concerning galaxy formation and evolution, much of it is verynew and rather sparse. The questions are just now emerging, and much more observational material needsto be gathered before the relevant issues can be well defined. What is the role of the environment ofgalaxies upon their evolution? What are the important aspects of galaxy interactions-near, distant, gaseous,and gravitational? If the implications from current data are true, what causes some galaxies to delay theirformation and others not to do so? Is there a single cause of galaxy formation? Why do some galaxiesbecome radio sources and others not? The answers to these and related questions will clearly involve manylarge-scale observing programs, which will require significant use of present and planned NOAO facilities.Fiber-fed spectrographs on medium and large aperture telescopes, two-dimensional infrared arrays, largeformat optical detectors, and enhanced state-of-the-art computing facilities will all be essential to theseprograms in the next five years.

3. Stellar Structure and Evolution

Pursuit of questions concerningstellar structure not only provides information about how stars evolve butalso sheds light on such diverse topics as star-formation, the chemical and dynamical evolution of thegalaxy, the calibration of the distance scale, and the age of the Universe. For example, J. Stauffer(Smithsonian Astrophysical Obs.) has obtained rotational velocities for stars in the Pleiades cluster. Hefinds that nearly half of the stars observed have rotational velocities much higher than expected. Thisindicates that a major portion of the angular momentum of the protostellar cloud is retained duringcollapse and is not shed into a circumstellar disk. Stellar spectroscopy is also raising questions about thedynamics of star-formation in the galaxy. J. Hesser (Dominion Astrophysical Obs.), W. Harris (McMasterU.), and R. Bell (U. of Maryland) have found variations in the chemical composition of main-sequencestars in the globular cluster 47 Tucanae. Such stars are thought to have formed at the same epoch; hence,these results raise questions about either the chemical homogeneity of the gas cloud that formed the clusteror about mixing within the stellar interiors. Further work is needed to determine the compositions of starsin globular clusters. The chemical composition of another class of stars, M giants in the galactic bulge,has been studied at CTIO by J. Frogel (KPNO) and A. Whitford (Lick Obs.), who find them to beextremely metal-rich and unlike stars near the Sun. Remarkably, these M giants are very similar to thestars in giant elliptical and SO spiral galaxies. This provides an opportunity to study a stellar populationsimilar to that of the largest galaxies in the Universe.

Spectroscopy of stars in our Galaxy is providing new and very interesting results that bear on theformation of the galaxy, and by implication, on the formation of all spiral galaxies. D. Geisler (CTIO) hasused NOAO telescopes to study star clusters in the galactic disk in the direction of the anticenter. He findsa population of metal-poor stars younger than those found in other parts of the disk, and this importantresult implies that the entire galactic disk was not formed at the same time but rather that the outerportions formed much later. A complementary result has been obtained very recently by K. Gilroy andC. Sneden (U. of Texas), C. Pilachowski (KPNO), and J. Cowan (U. of Oklahoma) in their study of r ands process elements in halo stars. By coupling their results with known nucleosynthetic processes in starsof differing mass, these investigators have been able to argue that the extreme halo population of stars inthe galaxy was formed in a very short time, about 10 million years. These two results have profoundimplications for models of galaxy formation, and they will provide motivation for additional observationaland theoretical programs in the future.

The above examples illustrate the broad range of stellar programs being carried out with NOAO facilities.For many of these problems, spectroscopy of more stars, intrinsically fainter stars, and more distant starsis needed. Among young star clusters, more work is required to understand the relation betweenstar-formation, stellar activity, and magnetic fields. Much remains to be done in the area of stellarevolution through the study of the surface compositions of stars at different phases of evolution and tounderstand the role of mixing. Scientific programs in the area of spectroscopy of stars in clusters willbenefit especially from multi-object capability, which will allow observations of many individual stars ina cluster simultaneously. Both CTIO and KPNO have multi-object fiber-fed spectrographs in operation.KPNO has just commissioned a bench mounted spectrograph which can be fed by up to one hundredindividually movable fibers. Demand for this instrument is extremely high. The designs of the WIYNTelescope, which will be placed on Kitt Peak, and of the proposed 8-m telescopes have been optimizedfor fiber spectroscopy.

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4. Star-Formation

In view of their proximity and the number of years devoted to their study, surprisingly little is knownabout how stars form. Processes involving the formation and evolution of the parent clouds, theirfragmentation and collapse, the role of angular momentum and magnetic fields, the establishment of theinitial mass function, and the evolution of protostars and very young stars are all areas of activeinvestigation. NOAO facilities have been used to observe regions of star-formation in our own and innearby galaxies, and the advent of two-dimensional detector arrays that operate in the infrared isstimulating even more observing programs relevant to this topic. Moreover, these arrays are particularlywell-suited for use in multi-wavelength, multi-observatory programs to address key questions in the areaof star-formation. In particular, theywillcomplement observations by HST,SIRTF, SOFIA,andmillimeterand sub-millimeter telescopes and arrays.

It has become well established that the collapse of a protostellar cloud to form a new star is accompaniedby an outflow of mass from the central region, and several programs have used NOAO observations toinvestigate the nature of these outflows and their implications for the star-formation process. Theseoutflows are usually anisotropic, often bipolar, and sometimes very highly collimated. An importantquestion, which has been examined by several groups, is the origin of this outflow and the mechanismfor its collimation. In some cases, the outflow is seen to be collimated to within 100 AU of the surfaceof the young stellar object but it is still unclear if the wind is intrinsically bipolar or whether it iscollimated by material around the star. Evidence that circumstellar disks are found around virtually allyoung stellarobjects has been obtained by S. Strom (U. of Massachusetts) and his collaborators, arguingfor an external collimation mechanism. However, additional data are needed. A successful understandingof this very commonoutflow phenomenon would provide valuable information about the role of angularmomentum in the star-formation process, about the efficiency of stellar collapse and the role ofcircumstellar material, and about the conditions at the surface of the young star itself.

Recent observations, again by the Stroms and their collaborators, suggest that the inner portions of disksaround protostars, which have masses of about one percent of the mass of the Sun, are essentially clearedaway over aperiod of about 107 years. What remains around main-sequence stars are disks with massesof about 10"° Mo, and these disks do not extend all the way to the surfaces of the central stars. Theobvious interpretation is that the disk material has aggregated to form planets. Again, detailed studies athigh spatial resolution and low-resolution infrared spectroscopy are required to explore the evolution ofstellar disks and hence to constrain models of the formation of planetary systems.

Anotherphenomenon related to the star-formation process is the Herbig-Haro objects, which are emissionline nebulae thought to originate from the interaction of matter ejected from a young star with theinterstellar medium. Observations are consistent with highly supersonic outflow, often accompanied bya larger-scale, less rapid outflow in the parent molecular cloud. It is not clear if the rapid outflow iscontinuous or intermittent, nor is the mechanism known which produces the high-degree of collimationthat is observed. Understanding of this phenomenon would shed light on the nature of both the youngstellar object and its environment

Productive areas for future investigation include both the local phenomena of protostars, mass outflow,circumstellar shells, and accretion disks, along with such global aspects as the initial mass function andthe variation of star-formation with changes in metallicity, turbulence, and magnetic fields. A majorimpetus for new and continuing programs in star-formation has come from the availability of

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two-dimensional infrared array detectors. Already these arrays have detected circumstellar disks ofmolecular gas around protostellar objects, and they have also revealed rich groups of very young starswhose existence was heretofore only assumed. Very recently, P. Hartigan and his collaborators at theCenter for Astrophysics have used a two-dimensional array to determine that molecular cooling is aprinciple energy loss mechanism in causing the deceleration of outflows from Herbig-Haro objects. Theseearly and tantalizing results are stimulating the formulation of many new observing programs.

A major new initiative in this area has been undertaken by KPNO astronomers using the four-colorinfrared imager (SQIID). This program involves a carefully constructed multicolor survey of selectedregions of active star formation, with the aim of producing an extremely useful database that will bereadily available to the astronomical community. Both the scientific objectives and the observing and datareduction strategies have been developed in consultation with outside experts in the astronomicalcommunity, and data are currently being taken for this project This program is but a first step in whatis seen as an era of major advances in the field of star formation, not only in our own galaxy buteventually in other galaxies such as the Magellanic Clouds and members of the Local Group. In the galaxyitself, the problem of low mass star-formation and the definition of the initial mass function (IMF) for lowmass stars can now be addressed. Studies of the upper end of the IMF, where many of the more massivestars have been heretofore obscured by the dust associated with their birthing process, have also becomepossible. It will be feasible to identify and study stars below the critical mass for nuclear ignition and toexamine accretion disks around protostars and young stellar objects. The arrays will also make possiblethe search for particle disks around main-sequence stars, these being the presumed progenitors of planetarysystems.

B. Initiatives for CTIO AND KPNO

1. Gemini

The Gemini project has as its goal the construction of two 8-m telescopes by the end of this decade. Oneof the telescopes will be located in Hawaii and will be optimized for infrared observations. The secondwill be located in Chile, probably on Cerro Pachon. Insofar as possible, it will be a twin of the Hawaiitelescope, but initial implementation of foci and instrumentation will probably emphasize opticalobservations.

The project is an international one, with the US providing 50 percent of the funding, the UK 25 percent,and Canada 15 percent Several options for the remaining 10 percent are now being explored. AMemorandum of Understanding among the partners should be signed during the spring of 1992.

The Gemini Board, which was appointed by funding agencies in the three countries, is responsible forsetting the policies governing the project. The NSF has been named the executive agency for theconstruction phase of the project and will use AURA as the managing entity. The Gemini project thusbecomes a third independent center of activity within AURA, with its position in the organization structureparallel to that of NOAO and STScI.

Because the Gemini project is being carried out under a separate cooperative agreement with the NSF,details of the project are described in separate documents and are not included in the NOAO long rangeplan.

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While the Gemini project is thus not a part of NOAO nor subordinate to it, NOAO is clearly a part of theGemini project. The scientific staff, especially at KPNO, is heavily involved in defining the scientificspecifications for the telescopes and working with the engineering staff to explore ways to achieve thoserequirements. CTIO staff is now carrying out a site survey at Cerro Pachon, and as the project develops,will provide logistical support and on site management for the project. Pat Osmer is on loan to the projectas Interim Project Scientist, and Fred Gillett is devoting most of his time to defining in quantitative termswhat IR-optimization requires. By international agreement, the time spent by scientists in the partnercountries is not billed to the project

In addition, NOAO has assumed responsibility for obtaining community input into the definition of thescience requirements for the telescope. We have set up committees to specify the optical and IRconfigurations, recommend the initial complement of instruments, and when costs are better defined,recommend priorities for what capabilities should be available at first light. Again, the activities of thevarious national communities are not supported by the project NOAO is supporting this activity withfunds in the NOAO director's office.

The approach to operating the telescopes remains to be defined. It is the intention of the participants tomake maximum use of the existing national observatories in order to minimize the costs of operations.Operations in Hawaii will be carriedout through the Joint Astronomy Center, which already operates theUnited Kingdom Infrared Telescope and the James Clerk Maxwell Telescope. CTIO will be responsiblefor operations in Chile.

In addition to operations at the sites, there is a need for a centralized management function, which willbe responsible for defining the overall Gemini program and taking the necessary recommendations to theGemini Board; managing the Gemini budget; allocating observing time; and maintaining the interfacestandards and commonality of instruments and software at both telescopes. In addition, there should beengineering staff associated with these centralized functions who could oversee outside contracts fortelescope upgrades, software development, and new instrumentation. Major new pieces of instrumentationwill not normally be fabricated on site.

We recommend that the headquarters for the Gemini telescopes be located in Tucson. Such a location isconsistent with the fact that the US is providing half the total funding for the project but moreimportantly, is consistent with the overall policy of integrating Gemini operations with existing facilitiesthat are already pursuing programs that are similar in kind. The Gemini staff and budget would beindependentof NOAO, reporting to AURA as the managing entity but taking advantage of the capabilitiesand resources already resident in Tucson. In terms of routine administrative matters, the project couldmake use of extensions of our accounting, payroll, and personnel systems. More importantly, the Geminiengineering and technical staff could be supplemented by contracting with NOAO personnel for specifictasks. In this way, the dedicated Gemini staff at the headquarters could be kept to a minimum while stillhaving access to the full range of expertise, including optical design and fabrication, detector testing andcharacterization, instrument design and specification, needed to operate complex modem telescopes at thelevels of performance specified for the Gemini telescopes.

Locating the Gemini headquarters functions in Tucson should not preclude but rather facilitate technicalcontributions from the partner countries. The headquarters should be primarily responsible for overseeingand integrating activities in the partner countries and for providing systems engineering as required.

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In addition, NOAO during the operations phase will continue to serve as the focal point for communityinput into the Gemini project maintain the national archive of Gemini data for US astronomers; supportremote observing at both Gemini telescopes; and encourage and assist community efforts to develop majorprograms that require substantial blocks of observing time. NOAO will, of course, bid on design andconstruction of Gemini instruments.

NOAO also plans to modify existing telescope control systems, data acquisition software, and datareduction programs, as well as its instrument interfaces, detector controllers, etc. to follow the Geministandards. In this way, the existing NOAO telescopes can serve as testbeds for new concepts, minimizingthe down time on the Gemini telescopes when new systems are installed.

2. WIYN

Following formal approval of the WIYN agreement by the NSF and university administrations, NOAOjoined together with the University of Wisconsin, Indiana University, and Yale University to form theWIYN Consortium, Inc., incorporated in the State of Arizona in November, 1990. The WIYN Project willmake use of a 3.5-m, spin-cast lightweight mirror produced at the Steward Observatory Mirror Lab. TheWIYN universities are prepared to contribute a total of S8.5M over the time period 1991-1994 for theconstruction of a new telescope on Kitt Peak. If Wisconsin, Indiana, Yale, and NOAO meet the obligationsdetailed in the WIYN agreement, the observing time remaining after the allocation of maintenance anddiscretionary time would be apportioned in the following way: Wisconsin 26%, Indiana 17%, Yale 17%,and NOAO 40%.

During FY 1991, the project staff grew to include a mechanical engineer, a systems engineer, and adesigner, in addition to the project manager. Design of the WIYN Telescope enclosure and controlbuilding was completed early in FY 1992, and general contractors were pre-qualified for construction. Siteconstruction is expected to start in mid-FY 1992 and continue through FY 1993. Fabrication of the WIYNTelescope mount will begin early in calendar year 1992 and continue with installation in FY 1993. Testingof the 3.5-m mirror polished to an f/1.75 sphere proceeded as part of the NOAO AOTT program (nowrenamed the 3.5-m Mirror Project). The mirror support system was fabricated, assembled, and testedsuccessfully. After thermal testing is completed in early FY 1992, the mirror will be figured to its finalform. NOAO anticipates that the mirror will be available for installation in the WIYN Telescope near theend of FY 1993. Also in FY 1993, the KPNO O/UV instrumentation program will complete modificationsof the multi-object spectrograph and fiber positioner in order to move the instrument from the KPNO 4-mtelescope to WIYN.

NOAO anticipates that the WIYN Telescope will provide the community with access to schedulingalternatives, such as service observing, queued observations, targets-of-opportunity, and long-term synopticand survey programs, all of which will enable new types of scientific research. The details of theseconcepts are under study within KPNO, in consultation with the user community, and implementationplans will be completed during FY 1993 and early FY 1994 as the telescope begins partial operations.

Key milestones of the WIYN project are as follows:

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WIYN Milestones

December 1991 Begin telescope fabricationFebruary 1992 Begin construction of enclosureMarch 1993 Enclosure completedApril 1993 Install telescope mountNovember 1993 Install opticsDecember 1993 First lightJanuary 1995 Full operation

3. 4-m Telescopes at CTIO

Plans are being made by two different groups for the construction of 4-m class telescopes at CTIO. Thefirst of these is the Southern Observatory for Astronomical Research (SOAR) 4-m telescope proposed bythe University of North Carolina and Columbia University. As currently planned, this telescope wouldemploy an altitude-azimuth mount similar in concept to the European Southern Observatory (ESO) 3.5-mNew Technology Telescope (NTT). The primary mirror would be an f/2 20-cm thick meniscus fabricatedfrom low-expansion ULE glass by the Coming Glass Works. Instruments would be semi-permanentlystationed at the two f/7.8 Nasmyth foci, with a rotating tertiary mirror providing rapid access to eitherfocus in order to accommodate quick changeovers from one instrument to another on a given night.Current strategy calls for North Carolina and Columbia to build the telescopes and instruments, althoughsome of the latter might be built at CTIO under contract. In return, NOAO would agree to operate thetelescope for some specified period of time. The exact division of observing time among the three partnershas yet to be specified, but the working plan is for this to amount to approximately one-third for each.Production of the ULE glass for the primary mirror was completed during FY 1991, and fabrication ofthe blank will begin once sufficient funds have been raised by the two universities.

The second telescope project being planned for CTIO is the 4-m Cambridge-Cambridge telescope proposedby Harvard University and Cambridge University. Although the planning for this telescope is still at anearly stage, significant progress was made on the fund raising front during FY 1991 in the form of a $3Mgift to Harvard University by the Arnold D. Frese Foundation of New York. It is likely that NOAO'sparticipation in this project would be more along the lines followed at Mauna Kea, with CTIO supplyinga site but charging for other services at cost In return, the NOAO community would receive somethingon the order of 15% of the observing time.

Plans call for these new telescopes to be located on Cerro Pachon, which is the tallest mountain on theAURA property in Chile. At an altitude of 2,725 m, Cerro Pachon is potentially a better site than Tololo(which is 500 m lower), particularly for mid-infrared observations. Located approximately 10 km to thesoutheast of Tololo, Pachon can be routinely reached by an unimproved dirt road in thirty minutes. Thesummit of Cerro Pachon is actually a 1.8 km dog-legged ridge, which could easily accommodate a numberof large telescopes. The north face of the mountain is a vertical cliff that faces into the prevailing wind.

In order to determine more precisely the site characteristics of Cerro Pachon, CTIO has initiated a sitesurvey of the mountain. With the help of financial contributions from the SOAR group, Harvard, and theBrazilians, the road to the summit was built and a shelter constructed for the observers in mid-1988.

Equipment from the NOAO Mauna Kea/Mt Graham surveys, including a weather station, infrared skyradiance monitor, micro-thermal tower, echosonde, and seeing telescope, has been used since 1989 to

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obtain modem data on the quality of the Pachon summit as an astronomical site. Analysis of thesemeasurements has confirmed that Pachon is an excellent site for infrared astronomy, indicating that themedian seeing at optical wavelengths is -0.6-0.7 arcsec (full-width at half-maximum). During FY 1991,a copy of the Las Campanas seeing telescopes was constructed and installed on Pachon in order to carryout more accurate seeing measurements and to provide a direct tie-in with the Las Campanas site testingresults. A second copy of the Las Campanas seeing telescopes will be installed on Cerro Tololo duringFY 1992 to allow simultaneous comparison of Pachon and Tololo. Current plans call for the testing ofPachon to proceed for two full years ending in 1993.

4. The 2 urn All Sky Survey (2MASS)

KPNO and CTIO are under consideration as the sites for the 2MASS project The goal of this project isto produce a uniform survey of at least 95% of the sky with 25,000 times greater sensitivity than theexisting Two Micron Survey. The survey will be in three near-infrared bands, J(1.25 urn), H(1.6 urn), andK (2.2 um) with goals of a 10 sigma detection of K = 14 point sources, 5% photometric accuracy, and1 arcsec positional accuracy. Such a survey is now feasible because of the availability of 256 x 256HgCdTe direct readout (DRO) infrared arrays coupled with the nearly one hundred-fold increase in thespeed of microprocessors and corresponding drops in the cost per Mbyte of memory that have occurredduring the past decade.

2MASS will revolutionize our understanding of the cool stellar population in both galactic and extra-galactic environments. The sensitivity of the survey to evolved stars as distant as 100 kpc will delineatethe structure of our own galaxy and establish the chemical characteristics of Local Group galaxies. Theview of distant galaxies, free of the zone of avoidance and internal extinction, will provide an excellentunbiased sample for study of the structure of the Local Universe. Finally, the impact of serendipitousdiscoveries associated with the enormous increase in survey sensitivity will surely be substantial.

The sky survey approach is to scan the 1.3-m survey telescope across the sky at a constant rate and tiltthe secondary mirror to freeze a sky image in the focal plane for an integration time of about 1.5 sec. Arapid reset prior to the next integration will follow. The tilt amplitude of the secondary is such that fiveoverlapping images with fractional pixel offsets of each sky position along a scan are obtained, allowingfor improved photometry as well as positions and corrections for the effects of bad pixels. Completecoverage of the sky is expected to take less than two years of observations.

Uniform full sky coverage requires survey facilities in both Northern and Southern hemispheres. Sitingof the survey instruments at KPNO and CTIO is currently under discussion.

Susan Kleinmann is the Principal Investigator and leader of the science team. The University ofMassachusetts has overall project responsibility. The Infrared Processing and Analysis Center (IPAC) isresponsible for the data reduction and processing. JPAC will also produce catalogs of point and extendedsource detections, an image product, and an archive of the raw data. The images, catalogs, and dataarchive will be readily accessible and will serve the community in the coming decades as major scientificresources.

The 2MASS project is currently supported for study and prototyping by the University of Massachusetts,NSF, NASA, and the Air Force. A proposal to the NSF and NASA for the project is currently underpreparation and is expected to be submitted before the end of FY 1992.

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A prototype camera and data acquisition system is being constructed for use with the KPNO 1.3-mtelescope, beginning in the spring of 1992, to obtain observations that demonstrate the 2MASS observingstrategy and performance goals and provide a database for support of early development and testing ofdata reduction and processing approaches.

5. Beyond 8-m Telescopes

Scientific progress in many forefront problems of astrophysics demands very high-angular resolutionobservations. This capability, when combined with high-spectral resolution observations and theunprecedented light-gathering power of large apertures, will permit breakthroughs in many scientificproblems. It will also complement and extend observations from the new generation of space-basedobservatories.

The scientific significance of high-angular resolution observations increases enormously with increasingbaseline. For example, the jump from 4-m to 8-m apertures allows fundamental progress in studies ofstellar and planetary formation. The further jump to interferometric baselines of 20 to 200 meters permitsthe detailed imaging of stellar surfaces and the measurement of supemovae diameters in the nearestexternal galaxies. Interferometric baselines of about 1 km will allow detailed imaging of the inner regionsof active galactic nuclei (AGNs) and quasi-stellar objects (QSOs).

NOAO believes that two key technologies must be developed before a national interferometric facility canbe defined. First NOAO will provide systems for the 8-m telescopes that will permit diffraction-limitedimaging up to their aperture limit by means of both passive and active observing techniques. Second,interferometers, consisting of three to five telescopes of medium aperture (0.5-3 m) on transporters, shouldbe developed for both infrared and optical wavelength regimes. These arrays would provide coverage oftelescope separations up to a few hundred meters. These arrays should be developed by universities orother groups outside NOAO. On the basis of results from these development programs, NOAO is preparedto join with others, as appropriate, to propose a national interferometric facility.

It may also prove feasible to merge the independent telescopes on the Mauna Kea site optically into anad hoc array, with very complete u, v coverage for separations up to 1 km. Optical fibers may be suitablefor retrofitting heterogeneous facilities for interferometric operation. Demonstration of interferometric fibercoupling of independent telescopes was first achieved between the auxiliary telescopes at the NSOMcMath facility on Kitt Peak in September 1991.

C. Instrumentation for CTIO and KPNO

One of the results of the formation of NOAO "has been a closer coordination of instrument developmentat the two nighttime sites. The responsibility for designing and fabricating TV acquisition systems, CCDcontrollers, and infrared instrumentation, for establishing high-speed data links, and for testing andcharacterization of detectors, has been assigned to one of the observatories. The designated observatoryhas then carried out the work on behalf of both. A prime example of this is the new project to mosaicCCDs, which is being carried forward at KPNO. This project will provide 2x2 mosaics of CCD detectorsfor both observatories and will lead to development of a larger 4x4 mosaic to be used in both the northand the south. Even in cases where the observatories have adopted different approaches to instrumentation,as with fiber-fed spectrographs, certain technology developments common to both projects have beenshared.

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This document presents a five-year plan for instrumentation at each observatory. In practice, these planscover the first four years in more detail than the fifth. Since it takes approximately two years to completea major instrument, four years is a natural planning cycle that encompasses this round of instruments andthe next. The plans are presented separately so that the evolution of instrumentation at the separate sitesis clear. Gose coordination of the two programs will continue, and the separate five-year plans haveserved to identify areas where cooperation is most likely to be both necessary and effective.

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1. CTIO Instrumentation

Table 1

CTIO Five-Year Instrumentation Plan Summary

FY 1993

2nd generation IRS (start)CCD mosaic prototype (finish)4-m seeing improvements (finish)4-m image analysis (finish)Implementation of large-format CCDs4-m secondary replacementImage stabilization cameraCCD controller production (continue)Computer improvements

Total

FY 1994

2nd generation IRS (finish)CCD mosaic (start)

4-m secondary replacement (continue)Implementation of large-format CCDsCCD controller production (finish)New spectrograph camerasComputer improvements

Total

FY 1995

4-m secondary replacement (finish)10 (im camera (start)CCD mosaic (finish)Implementation of large-format CCDsNew spectrograph cameras1 instrument upgrade projectComputer improvements

Total

FY 1996

10 um camera (finish)Remote observing (start)Implementation of large-format CCDsTelescope/image improvement2 instrument upgrade projects (1 major)Computer improvements

Total

CTIO Project Manpower CapitalSdentist(s) (months) ($1000)

Elias, Gregory.Elston 47 50

Walker et al. 14 15 *

Baldwin 15 15

Baldwin et al. 23 20

Walker et al. 15 40

Baldwin, Weller 15 70

Suntzeff et al. 19 28

Ingerson, Walker 35 55

Staff 2 _80185 373

Elias, Gregory, Elston 25 55

Walker et al. 20 55 *

Baldwin, Weller 55 120

Walker et al. 20 30

Ingerson, Walker 35 55

Staff 25 25

Staff _2 _85182 425

Baldwin, Weller 20 15

Elias, Gregory 35 75 *

Walker et al. 35 120 *

Walker et al. 30 70

Staff 25 25

Staff 30 25

Staff _2 _90177 420

Elias, Gregory 35 80 *

Ingerson et al. 25 50

Walker et al. 30 70

Staff 25 40

Staff 65 75

Staff _5 100

185 415

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FY 1997

Remote observing (continue) Ingerson et al. 15 20Implementation of large-format IR array Elias, Gregory 25 80Implementation of large-format CCDs Walker et al. 30 80Telescope/image improvement Staff 25 403 instrument upgrade projects (1 major) Staff 85 95Computer improvements Staff __5 100

Total 185 415

* Joint project with KPNO or duplication of KPNO instrument. Only CTIO resources are indicated.

In addition, CTIO expects to bid on the fabrication of one instrument for the Gemini telescopes, with workbeginning approximately in FY 1994.

During FY 1992-1997, work in instrumentation at CTIO will concentrate on two main areas: takingadvantage of improvements in detector technology, and improving telescope/instrument performance inorder to realize the full potential of CTIO as an astronomical site. In addition, advances in computer andcommunications technology appear to be nearing a point where large-scale computer networking andremote observing are feasible, as well as a new generation of more powerful and flexible instrument anddetector controllers.

Since the introduction of CCDs for astronomical use in the late-1970s, their area has doubled roughlyevery five years. New fabrication methods have led to quantum efficiencies that are close to the theoreticallimit. Reductions in read noise and improved charge transfer efficiency have led to greater sensitivity forlow-background applications. For many observing programs, these gains translate into several-foldreductions in the amount of observing time required. High-efficiency CCDs are now available in formatsas large as 2048 x 2048 and (very soon) 1024 x 3096, with imaging on still larger scales possible throughmosaicing of specially-produced chips. Much of CTIO's instrumentation effort will be aimed atimplementing these new detectors as they become available. In many cases they can be easily retrofittedinto existing instruments. In other cases, as with large mosaics for imaging, a new instrument must bebuilt

In the infrared, the impact of two-dimensional arrays has been dramatic. Observers have gone abruptlyfrom having a single-channel detector to having thousands of such detectors; as a result, projects that werepreviously major endeavors on the 4-m telescope have become routine on the 1.5-m telescope, while the4-m telescope, equipped with the new arrays, provides the capability to carry out projects that were noteven contemplated a few years ago. In the infrared, array technology continues to improve, with detectorareas doubling on time scales of approximately two years. The first near-infrared arrays (InSb) purchasedby NOAO, which were delivered in 1987-1988, are only 58 x 62. Currently, arrays as large as 256 x 256are available-or nearly so-in a number of materials, with some prospect of still larger arrays in the nearfuture. CTIO is actively pursuing implementation of these second-generation arrays. In addition, arraysfor the mid-infrared (10 um) are now fairly mature, and the costs of data-handling hardware havedecreased to the point where efficient array-based instruments for this wavelength region are practical.

Starting in FY 1990, we began work aimed at achieving superb image quality with the CTIO telescopes.The original site surveys indicated that Cerro Tololo routinely has sub-arcsec seeing; the twenty-fifthpercentile figures are better than 0.5 arcsec. Our long-term objective is to obtain similar image quality in

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the focal plan, starting with the 4-m telescope. Work to eliminate anything in the dome or telescope thatmight produce seeing degradation, principally through generation of excess heat was begun in FY 1990and will continue through FY 1993. In addition, various projects are intended to improve the opticalperformance of the telescope itself. Infrared imaging with the f/30 secondary has shown that the primarymirror is capable of producing images with 0.35 arcsec FWHM, or better. The new 4-m PF corrector,scheduled for completion in FY 1992, should produce images of this quality over a 50 arcmin field at theprime focus. However, roughly sixty percent of the use of the 4-m telescope is at the f/7.8 R-C focus,where the image qualityachieved in practice tendsto be significantly worse. An extensive testingprogram,carried out during FY 1991, indicates that the present f/7.8 secondary has a poor figure and thatperformance would significantly improve if it were replaced by a mirror with better figure. Furthermore,both our understanding of the 4-m telescope and experience elsewhere, most notably at the ESO NTT,suggest that additional gainsshould be possible with replacement of the existingwide-field secondary witha smaller active secondary. This project, which will take place over three fiscal years, includes design andconstruction of an active secondary and associated control hardware and software, including use of thesecondary for guiding.

Optical InstrumentsThe acquisition of larger and better CCDs continues to be a central theme whenplanningfor future opticalinstrumentation. NOAO received a few 2048 x 2048 Tektronix detectors during FY 1991, but these willonly fill the most pressing needs for large-format CCD detectors. Given their high price tag, $110K fora chip with four good amplifiers, it seems unlikely that all requirements can be filled through additionalpurchases from Tektronix. Instead, CTIO has joined with KPNO and Steward Observatory to obtaincustom CCDs fabricated by Loral (ex-Ford Aerospace) of 3072 x 1024 pixels (15 urn pixel size), plusadditional smaller devices. The production run was successful, and the thinning and packaging effort isnow underway. Results to date appear promising, but thinned science-grade chips in the larger size havenot yet been produced. A similar production run is currently planned to produce detectors potentiallysuitable for a mosaic imager, although somewhat different arrangements for thinning and packaging willbe necessary. The instrument development plans described below presume the availability of roughly adozen large-format CCD detectors at CTIO over the next three to five years.

The first project is the construction of a new prime focus imager. In its initial form it will accommodateCCDs as large as the Tek 2048 x 2048. The design is flexible enough to allow imaging with a mosaic ofCCDs up to 110 mm across. In addition, it will be possible to do "short scanning" with the new imager(i.e., clocking out the CCD a line at a time while simultaneously moving the CCD relative to the star bythe same amount). The basic instrument is scheduled for completion in FY 1992, and the additionalcapabilities will be added as needed.

CCDs larger than the Tektronix 2048 x 2048 chips (55 mm) are at least several years in the future, giventhe apparent lack of any commercial or military incentive for their production. Therefore, in order to coverwider fields at a resolution sufficient to sample star images adequately in sub-arcsec seeing, a mosaic ofCCDs will be required. A project to construct a large CCD mosaic is currently being pursued jointly byKPNO and CTIO. It can be divided into two major phases. The first comprises a production run of2048 x 2048 CCDs, packaged so as to permit them to be buttable, or nearly so, on four sides. These chipswould probably have pixel sizes of approximately 15 urn. If this run is successful, two prototype mosaics,each containing a 2 x 2 array of these chips, would be produced-one each for CTIO and KPNO.

The decision on how to proceed on the next phase of the project would be based on the degree of successof the prototype, including factors such as detector yield. Under ideal circumstances, a 4 x 4 array of

21

2048 x 2048 detectors with 15 urn pixels would be desirable, since this corresponds to proper samplingof the full field of the 4-m prime focus in good seeing. Provided projected costs are reasonable, twoinstruments would be constructed; an alternative would be to build a single instrument that would beshared between KPNO and CTIO.

It should be noted that one of the problems associated with such a large mosaic is simply that of handling,processing, and storing the data; a single exposure will generate 128 Mb of data. Preprocessing of the datais thus virtually mandatory. Tyson (Bell Labs) has designed a dedicated preprocessor capable of generatingin near real time a composite frame from which all instrumental signatures have been removed. We willeither duplicate Tyson's hardware or produce a functionally equivalent system within the framework ofour CCD/IR Array Controller projects. We expect the first phase of this project to be carried out inFY 1991-1993, and the second phase in FY 1994-1995.

For optical spectroscopy, the availability of the new, large-format CCD detectors will require, at aminimum, construction of new spectrograph cameras for the three telescopes currently used forspectroscopy (the 4-m, 1.5-m, and 1.0-m). The spectrographs themselves are generally adequate for usewith large-format CCDs, although there is interest in a high-throughput, medium resolution instrument forthe 4-m, which might be undertaken as the "major instrument" listed in FY 1994 or FY 1995, particularlyif the development can be done jointly with another institution or telescope, such as SOAR. In addition,the efficiency of observing will be improved if key functions on the spectrographs are automated, whichis now the case only for the 4-m Cassegrain spectrograph; the 4-m echelle, the 1.5-m, and 1.0-mspectrographs have very limited remote capabilities.

We do not plan to construct any major new fiber-fed instruments in the mid-term, but we will continueto work to improve the efficiency and flexibility of the bench-mounted spectrographs. For example, webelieve that fiber technology will continue to improve, allowing us to replace our present fibers with fibersthat will work farther into the ultraviolet.

Infrared Instruments at CTIO

The present generation of infrared instruments at CTIO uses arrays with 58 x 62 pixels. CTIO'sinstrumentation plans in the infrared are focused on making full use of larger format arrays, which are alsoexpected to have smaller pixel sizes, lower read noise, and lower dark current.

The current complement of array-based instruments at CTIO comprises a 1-5 um imager and a 1-5 umspectrometer. We intend to replace these with second-generation instruments and to add a 10 um imagingcapability during the next three to four years. In the longer term, we expect that 512 x 512 arrays willbecome available, either as single devices or as buttable arrays. We will design our second-generationinstruments to accept these larger arrays whenever possible.

CTIO has started construction of a simple second-generation imager. The instrument will include two filterwheels, allowing use of a reasonable number of discrete filters, but will have no provision for more exoticfeatures such as a coronagraph, Fabry-Perot etc. The optical design will permit use of the imager at theCassegrain foci of most CTIO telescopes, thus providing a range of pixel scales and field size. Thedetector will be a Rockwell NICMOS III HgCdTe array, which is 256 x 256 with 40 um pixels; this arraywas ordered at the end of FY 1991.

Upon the completion of the second-generation imager, CTIO will construct a second-generation IRspectrometer. The new instrument will have an optical design better matched to the larger formats and

22

smallerpixelsof second-generation arrays. We anticipate only a small increase in the physical size of theinstrument The spectrometer would be optimized for the CTIO 4-m telescope. It would have resolutions(2-pixel) from R = 200-3500, plus a non-dispersing imaging mode. Slit length would be nearly 3 arcminon the CTIO 4-m telescope and 8 arcmin on the 1.5-m telescope. It is our intention to design theinstrument to be usable on the KPNO telescopes, which would permit KPNO to copy the design. The idealarray for such an instrument would be a 256 x 256 InSb array, with a HgCdTe array being an acceptablealternative.

KPNO intends to begin design of a 10 um imager in the latter part of this five-year plan. CTIO willconstruct a duplicate of the KPNO instrument. A 10 um imager should provide diffraction-limited (0.5arcsec) imaging on the CTIO 4-m telescope.

Active Secondary for 4-m TelescopeThe time needed to observe a given object in a background-limited situation depends just as much onhaving small images as it does on having a large aperture. The success of the ESO NTT telescope amplyhighlights the fact that the image quality at the NOAO 4-m telescopes needs to be improved if we are tocompete with other telescopes, even of the same size. One specific problem is our f/7.8 secondary. Recentmeasurements show that it limits the Cassegrain images to about 0.6-0.7 arcsec FWHM even under thebest seeing conditions, whereas we know that with the f/30 secondary we can sometimes see images assmall as 0.35 arcsec FWHM (at 1.6 um). The poor performance of the f/7.8 secondary is thought to becaused by a combination of residual errors in the figure, including a "best focus" position that isincompatible with existing instrumentation, support problems, and coma produced by alignment changesas the telescope is moved around the sky. We propose to cut through this interrelated set of problems byacquiring a new, smaller secondary (designed to cover a smaller field on the sky) that would be activelycontrolled along the same lines as the NTT secondary. The three parts of the project will be to fabricatethe new secondary, to build the mechanism at the top end of the telescope which will allow remoteadjustment of the secondary, and to install a Shack-Hartmann image analyzer at the Cassegrain focus(probably utilizing the existing offset guider probe). Results from the NTT show that adjusting thesecondary to remove alignment and focus errors produces essentially as much improvement in image sizeas does the active deformation of their primary. Our goal is that the improvements to our own secondary,along with better control of dome and mirror seeing, will lead to about fifty percent smaller images (amedian value of 0.7 arcsec FWHM, as compared to our present 1.4 arcsec FWHM). This would let usobtain spectra of faint objects twice as quickly as at present making much better use of the excellentqualities of the Cerro Tololo site.

The installation of the image analyzer will begin in FY 1992, while the secondary fabrication will bestarted in FY 1993. A possible alternative of refiguring the existing secondary will also be explored.Although this possibility offers obvious potential time and cost savings, the 4-m telescope would berestricted to prime focus and IR instrumentation while the secondary is being refigured.

Additional ProjectsCTIO has begun to provide the high-speed networking capabilities that will be needed to support remoteobserving and data transfer. At present the La Serena-Tololo microwave link provides a high-speed linkbetween the La Serena and Tololo computer networks, and a 56 Kbaud satellite link between Cerro Tololoand the Internet is also operational. The latter has been funded by NASA for three years to improvecommunications with astronomical institutions in the Southern hemisphere and to support experiments inremote observing. The satellite link is already used extensively for real-time interaction with remotecollaborators during observing runs, data transfer, and related applications. The present bandwidth is not

23

adequate for true remote observing. Even if the bandwidth were available, we do not have sufficienton-line control of the instrumentation to permit efficient remote observing. We expect to remedy both ofthese deficiencies during the latter portion of the five-year period, in part because of the increased demandthe Gemini project will also be placing on these facilities.

CTIO has spent the past few years developing a new generation of detector control systems. These newarray controllers are far more powerful than what is being used now at CTIO and will be more flexibleand reliable, as well as cheaper to replicate. They will also permit a high degree of compatibibty betweenIR and CCD controllers. Production of the new controllers will begin during FY 1992 and will extendthrough FY 1994.

24

2. Kitt Peak National Observatory

Table 2

KPNO Infrared Five-Year Instrumentation Plan

KPNO Project Labor CapitalScientist (mm) ($K)

FY 1993 ProgramComplete proto high res spectrometer Hinkle 52 64

Upgrade CRSP Joyce 43 14

Design JHKL spectrometer (GrASp) Joyce 55 90

Detector R&D Gadey 35 46

Mass buy 256 x 256 high QE deteaorsTotal 785 214

FY 1994 ProgramUpgrade SQITD Merrill 25 40

Continue JHKL spectrometer (GrASp) Joyce 75 85

Fast electronics upgrade Merrill 55 93

Detector R&D Gatley 35 46

512 x 512 detector developmentTotal 790 264

FY 1995 ProgramDesign medium res spectrometer Hinkle 85 90

Upgrade COB Probst 45 85

Complete JHKL spectrometer (GrASp) Joyce 25 45

Detector R&D Gatley 35 47

512 x 512 detector developmentTotal 790 "267

FY 1996 ProgramContinue medium res spectrometer Hinkle 75 85

Design 10 um camera Gatley 60 90

Fast electronics upgrade Merrill 20 45

Detector R&D Gatley 35 47

Detector developmentTotal 790 267

FY 1997 ProgramComplete medium res spectrometer Hinkle 80 90

Continue 10 um camera Gatley 65 95

Design 10 um spectrometer Joyce 20 40

Detector R&D Gatley 35 53

Detector developmentTotal 200 278

25

a. KPNO Infrared Instrumentation

Infrared astronomy has experienced a technological revolution with the introduction of infrared arraydetectors. The ability of NOAO to lead this revolution stems direcdy from the vigorous research anddevelopment program in Tucson. We expect that the research and development effort will continue todrive the infrared program for the foreseeable future.

Research will focus on acquisition, evaluation, and operation of new detectors. In the near infrared, the1-5 um interval, dramatic improvements in both format size and noise performance are confidendyexpected. Development of instruments deploying these new detectors will emphasize, where possible,commonality of design, based on the novel concept of the Cryogenic Optical Bench. Designs will bemodular, support plug-in detector upgrades (including the anticipated format size increases), and utilizeclosed-cycle refrigeration.

Upgrades in both computer hardware and software, and in the speed of instrumental electronics, will berequired in order to provide reduction and archiving capabilities consistent with these innovations. Thefast readout required for large-format devices sensitive in the thermal infrared creates stringentrequirements for large bandwidth. A new f/15 secondary mirror at the 4-m telescope and small activesecondaries capable of fast guiding at the 4-m and 2.1-m telescopes will be needed for optimal operation.

The KPNO Infrared Program is well-positioned to meet the requirements of the Gemini 8-m telescopes.The fast guiding and coatings endeavors are directly applicable to the design of an "infrared optimized"telescope. By virtue of the Cryogenic Optical Bench approach to instrument construction, the presentgeneration of KPNO instruments can be regarded as prototypes for the 8-m telescopes. In imaging, thelong-term effort will be in the area of diffraction-limited observations with associated adaptive optics, fastelectronics, and rapid guiding. High resolution spectroscopy can benefit significantly from a successfuladaptive optics program because of the small angular slits required to achieve high spectral purity. A planincluding development of sharply improved image quality and spectroscopy is therefore operationallyjustified.

Status at the end of FY 1991

Recent development efforts have capitalized successfully on the availability of large format near-infraredarrays. The novel SQIID imager, which uses four 256 x 256 PtSi detectors to view the same area of thesky simultaneously in J, H, K, and L (1.2, 1.6, 2.2, and 3.5 um), is now available as a visitor instrument.This large field of view camera is used primarily in a "telescope raster" mode to build up images of asquare degree or more in size. An additional capability for simultaneous J, H, K imaging polarimetry hasalready been demonstrated with SQIID; this function is enabled by the addition of a warmsuper-achromatic half-wave plate and cooled analyzer. Gosed cycle coolers remove the need for liquidhelium in this and all subsequent IR instruments. The SQIID project is a good example of the cooperativemode of operation between NOAO and other institutions, in that Space Telescope Science Instituteprovided some capital for the detectors and participated in the science planning for the instrument, as wellas in the science verification.

To install SQIID on the 4-m telescope requires some upgrading of the performance of the telescope interms of pointing and tracking, along with the installation of the plumbing for the closed-cycle cooling.To simplify the optical design of SQIED, the decision was made to accept one standard focal ratio, f/14.The alternative of f-ratio conversion optics for use at the 4-m was rejected because of significant

26

degradation of throughput, serious strain on the instrumental envelope in getting the focal plane far enoughinto the dewar, and operational complexity in mechanical and optics changes for different telescopes. Theinstrument currently cannot be used on the 4-m telescope. A new IR secondary will be figured to provideuniformity of ER operations across the mountain; the project involves the optical work on an existing blankand reactivation of a secondary mounting originally built into the telescope. The upgrade is scheduled tobe finished by the end of FY 1992.

With the conclusion of the SQIID project, attention will return to completion of the Cryogenic OpticalBench, a second-generation infrared camera with detector and filter complement emphasizing narrow-bandimaging and low-dispersion spectroscopy in the 2 um window. The filter complement provides for about30 discrete filters. These include two novel innovations: a linear-variable filter covering the 2 um windowat 1.5% resolution, and a solid state, linear-variable Fabry-Perot etalon with R -700. A grism isincorporated for long-slit spectroscopy at R ~100, and coronagraphic stops may be placed in the cold focalplane. Finally, there is a polarizer-analyzer combination for JHKL polarimetry.

Work on the Cryogenic Optical Bench was halted in 1989 in order to build SQIID, thereby, takingadvantage of the situation created by the availability of PtSi arrays; the tasks remaining are theconstruction of the dewar shell and the basic mechanical structure, along with the electronics. These arestraightforward copies of the modules in SQIID and should be completed in the first half of FY 1992.

Development of fast electronics was begun in FY 1990, and the prototype was available and working inthe L channel of SQUD by the end of FY 1991. Fast processing electronics are essential for operation inthe thermal infrared, for rapid data acquisition, for fast guiding, and for more sophisticated adaptive optics.Faster electronics will also be needed for full exploitation of the multiple-read noise reduction algorithm,essential for efficient spectroscopy. KPNO plans to continue development work and upgrade in this crucialarea.

Five-Year Plan

Diffraction-limited ImagingInfrared astronomers are becoming increasingly aware of the potential of adaptive optics for imageimprovement. The recent demonstration of diffraction limited imaging at 2-5 um at Haute Provence, amediocre site, has shown that this potential will be realized within the near future. The 2 um window isa particularly good place to work because the background from both atmospheric airglow and thermalemission is relatively low. The KPNO Infrared Program will enter this field with a phased developmentprogram that begins with relatively simple modifications to existing facilities and instruments. The firststep will be adaptive correction to image motion through simple tilt correction, which should reduce the2-3 um image diameter by a factor of two in Kitt Peak median seeing. This approach will then begeneralized to higher order wavefront correction with the addition of a segmented mirror and withimproved wavefront measurement

The first step is proceeding at the 2.1-m telescope under contraa with the Gemini project A CCD camerawill be used to provide a continuous position readout for the reference star, which may be any star in thefield. The required brightness of the reference source will depend on atmospheric conditions but will besufficiently faint to ensure wide applicability of the image stabilization option. The error signal will beused to close a fast guiding loop with the existing 2.1-m two-axis IR secondary.

Implementation of the fast guiding requires installation of suitable mirrors, first at the 2.1-m and later atthe 4-m. A focal ratio in the range f/60 to f/120 is appropriate for this small secondary. An upgrade of

27

the fast processing electronics will be required for rapid centroiding and generation of the error signal todrive the mirror tilt in two axes.

The longer term developments include deployment at the 4-m of the tilt correction system andincorporation of higher order corrections through active control of a segmented mirror. Following themodel of other successful IR development programs, development of a mirror with 10-20 actuators couldbe undertaken jointly with a commercial vendor, especially one with experience in adaptive optics fordefense programs. Real-time correction of several higher order (Zemike) terms would then be possible andthe goal of diffraction limited imaging more closely approached.

SpectroscopyThe experience gained at KPNO with CRSP, a low- and medium-resolution array spearometer employingan SBRC 58 x 62 InSb array, amply demonstrates the power of IR arrays for spectroscopy. The opticaldesign for the high resolution (R = 100,000) long-slit spectrometer (HRIS) is now complete, and work isproceeding on the mechanical design. This instrument will continue the strong tradition of high resolutionIR spectroscopy begun at KPNO with the 4-m FTS, and because of the improvements in deteaortechnology, will provide much greater sensitivities. For this reason, it will also be effective to use HRISon the 1.3-m and 2.1-m telescopes.

As high quantum efficiency, large format detectors become available, the deteaor in CRSP can beupgraded as a short-term measure preceding the construction of a next generation medium resolutionspectrograph, scheduled to occur toward the end of the five-year period. This strategy will allow us thetime needed to fill an important gap in our spectroscopic arsenal by building an instrument that measuresall of the J, H, K, and L windows simultaneously: the Grating Array Spectrometer (GrASp). Thisinstrument will provide survey-mode capabilities for spectroscopy analogous to those SQIID gives forimaging. GrASp will employ initially four 480 x 640 PtSi deteaors, one array covering each of the fouratmospheric windows between 1 and 4 um. Thus, as it did in the step toward the 256 x 256 generationof deteaors, the early availability of larger format PtSi technology will allow us to proceed expeditiouslyto the construction of innovative instrumentation.

Detector Research and DevelopmentIt is crucial that NOAO continue to support a vigorous research and development effort in arrayacquisition, evaluation, and operation. All of the IR instruments will profit enormously from utilizationof high quantum efficiency deteaor arrays. SBRC has developed a commercially available highperformance 256 x 256 InSb array. High performance HgCdTe 256 x 256 arrays for wavelengths less than2.5 um have been produced for the NICMOS instrument Although some operational issues may need tobe resolved to minimize effects dependent on exposure history, these deteaors have yielded valuablescientific results on ground-based telescopes. They can currently be ordered from Rockwell. It is essentialthat planning include the purchase of one or the other of these array types. They must be tested andverified for use in the Cryogenic Optical Bench, for upgrade of the CRSP spectrometer, and for use in thePrototype High Resolution Spectrometer. InSb is the first choice because of its wider wavelength coverage.

Further in the future, the subsequent generation of IR arrays will advance in two areas: 512 x 512 arraysfor the 1-5 um regime and larger format arrays for the 10 and 20 um regimes, with large pixel capacityto accommodate the very high photon background.

Direct imaging at 8-14 um is crucial for a detailed understanding of the physical conditions in heavilyobscured regions such as the nuclei of interacting galaxies and the disks around protostars. At long

28

wavelengths the extinction is greatly reduced, broad spectral features arising from the dust are present, andthe flux from many dust-enshrouded objects is at a maximum. The high spatial resolution of aground-based 10 um camera will reveal the detailed morphology of the sources discovered by IRAS.Detailed comparison with optical and radio images will show clearly where the hot dust lies.

At 10 um the Airy disk radius on the 4-m telescope is comparable to typical seeing (which is half thatencountered in the visible), so that diffraction limited imaging is possible. Photometry with arrays hasadvantages over conventional aperture photometry in the thermal infrared; the effective aperture size canbe tailored in post facto analysis to a value dictated by the seeing, and so minimize the thermalbackground.

The advantages of array technology for infrared astronomy have been amply demonstrated by the 1-5 umimagers recently commissioned at KPNO and CTIO. The 10 um camera is a logical extension of thosecapabilities. Based on previous experience, the plan is to build a 10 um camera that incorporates lowresolution long-slit spectroscopy (with a grism), polarimetry, imaging spectroscopy (with a Fabry-Perot),and a stellar coronograph; the design will be based on the Cryogenic Optical Bench concept The deteaorwill be an Impurity Band Conduction (IBC) array under development by Hughes-Carlsbad and Rockwell.There are 20 x 64 test devices currently in-house. A reasonable guess at future format expansion will be58 x 62. These devices can cover the 8-27 um range. Since the deteaor wells saturate in about 1 ms, thecontinuing development of the fast electronics is critical for rapid readout and partial real-time processing.

Advanced mirror coatingsThe performance of all the IR instrumentation is affected by the reflectivity and emissivity of the telescopeoptics. The optical design of the telescope system, the intrinsic properties of the mirror coating, thecontamination of the mirror surfaces by dust and other residues, and the deterioration of the mirrorsurfaces are all important faaors in determining the system emissivity, and thus the ultimate performanceof the IR instrumentation. In the thermal IR, notably around 4 um and 11 um (and perhaps even in theK band), the thermal emission of the telescope system is the dominant source of background at thedetector.

KPNO is planning a program to evaluate the performance of telescope mirror coatings. In FY 1991, weinitiated the effort by applying an advanced coating to the optics of the existing 13-inch f/15 low-background telescope~a telescope currently stored in the IR lab—and adapted the telescope tube so thatit can be attached to the top-surface of the IRIM and CRSP. The telescope is now stored in the 1.3-mdome, and measurements of the 13-inch telescope emissivity, zenith sky emissivity, and 1.3-m telescopeemissivity at 4 um are made each time the IRIM or the CRSP is mounted on, or removed from, the 1.3-munder clear weather conditions. Use of the 13-inch telescope for these tests allows us to isolate sourcesof background emission in the telescope, recoat the mirrors, change coatings, and make mirror cleaningand scattering tests-all of which would be rather impractical with the 1.3-m telescope itself-while at thesame time providing a realistic approximation to a real telescope environment and configuration.Comparisons can also be made with the aluminum coatings on the 1.3-m.

The coating now being tested is thorium fluoride/silver/chromium, which the NOAO coating lab is ableto produce. This prescription has been in use at the 4-m FTS for several years. If the testing indicatessubstantially improved durability and performance of advanced coatings, it will be important to developthe capability to lay down silver undercoated with copper and overcoated with sapphire and tantalumoxide. This formula was the best one devised by the Optical Sciences Center, which was under a NOAOcontraa to develop an IR optimized, broad wavelength, improved durability mirror coating.

29

Table 3

KPNO Optical/Ultra-Violet Five-Year Instrumentation Plan

FY 1993

Complete 4-m wide-field cameraContinue 4x4 CCD mosaic

CCD development programFabricate 2 new CCD controllers

Faber R&D program1 or 2 instrument improvement projects

Total

FY 1994

Start wide-field guider-rotatorsContinue 4x4 CCD mosaic

(compute rs/CCDs)CCD development programFiber R&D program1 or 2 instrument improvement projects

Total

FY 1995

Continue wide-field guider-rotatorsContinue 4x4 CCD mosaic

CCD development programFiber R&D program1 or 2 instrument improvement projectsNew instrument projects

Total

FY 1996

Complete wide-field guider-rotatorsCCD development programFiber R&D program2 or 3 instrument improvement projectsInterferometry R&DNew instrument projects

Total

FY 1997

CCD development programInterferometry R&DFiber R&D programInstrument improvement projectsNew instrument initiatives

Total

KPNO Project Labor CapitalScientist(s) (mm) ($K)

Jacoby, Boroson 5 80

Boroson et al. 40 25

Boroson 25 30

Green et al. 5 15

Barden 2 5

Staff 10 5

87 160

Staff 15

Boroson et al. 40 200

Boroson 25 35

Barden 2 5

Staff 10

92

5

250

Staff 30 10

Boroson et al. 20 20

Boroson 25 35

Barden 2 5

Staff 20 20

Staff 150

~97 240

Staff 20 10

Boroson 25 35

Barden 2 15

Staff 40 30

RidgwayStaff

20

707

100

70

260

Boroson 40 40

RidgwayBarden

20

2

100

15

Staff 30 40

Staff

~92100

295

30

b. KPNO Optical-Ultraviolet (O/UV) Instrumentation

During the last few years, the Kitt Peak O/UV instrumentation program has focused on the developmentof a multi-objea spectroscopic capability for the 4-m telescope. Our first effort was the adaptation of theLockheed camera at the R-C focus to hold fiber optic plugboards; two fiber optic cables, optimized forthe red and the blue spectral regions, were also built Following the commissioning of "Nessie," we beganthe design and fabrication of an automatic fiber positioner for the 4-m R-C focus. An x-y stage and arobot gripper were used to locate magnetic fiber buttons in the telescope focal surface. A multi-objectspectrograph designed for use with optical fibers and large-format CCD deteaors was also designed foruse with the automatic fiber positioner. Both of these new instruments, the fiber positioner and the fiberoptic bench spectrograph, were nearing completion at the end of FY 1991.

Beginning in FY 1992, our full attention will be focused on advances in imaging capability, especiallyat the 4-m telescope. During the period from FY 1993-FY 1997, we expea to allocate the majorityof ourinstrumentation resources to developing a wide-field CCD mosaic imager in collaboration with CTIO.

A program to upgrade deteaors used with Kitt Peak instruments to larger formats, lower noise, and highersensitivity will continue. A major goal is to support the program to build a 2 x 2 mosaic of CCDdetectors, each with 2048 x 2048 large or 4096 x 4096 small pixels for use on the 4-m telescope for wide-field imaging. We also expect to upgrade and/or replace our CCD controllers with more modemarchitecture, following the new controllers under development at CTIO, and to develop a Sun-based userinterface.

In addition, a number of projects aimed at enhancing existing capabilities at the 4-m and smaller KPNOtelescopes will be considered. These might include, but are not limited to the following:

• A superdensepak fiber cable.

• Cross dispersion for the bench spectrograph.

• A new camera for the R-C spectrograph to increase throughput.

• A germanium array detector to bridge the gap between optical and near-IR.• A reconfiguration of the R-C spectrograph to allow observations with a cross dispersed echellette.

• A CCD spectrograph (equivalent to the "Goldcam") at the 0.9-m telescope.

• Upgrade of imaging capability at the Schmidt telescope to take advantage of the 1° field achievablewith the new 2048 x 2048 CCDs.

• Modification of the 4-m prime focus corrector to improve the images over the wide field sampled bythe CCD mosaics.

• Modification of the 2.1-m and 0.9-m guiders to allow wider field.

Finally, during the period including FY 1993-FY 1997, we will continue a program of R&D with opticalfibers intended to lead to better use of fibers on Kitt Peak and to the development of instrumentation forthe WIYN Telescope and the Gemini 8-m telescopes.

The scientific motivation for a wide-field CCD mosaic is strong, especially for galaxy photometry, studyof nearby galaxies, and deep sky survey programs. When 8-m telescopes come on-line, the 4-m will beused very heavily for imaging; it will be a valuable instrument to "find" objects to observespectroscopically with the 8-m telescopes. The proposed device would consist of a 4 x 4 array of Ford

31

chips (2048 x 2048 with 15 um pixels) covering 0.41 square degrees with a pixel size of 0.28 arcsec,sufficiendy small to sample the best seeing. A small 2x2 array of such chips will be made as apreliminary demonstration of the technology. Such a mini-mosaic will allow us to learn how to interfacemultiple chips both mechanically and electrically. Since it will fit into a standard universal dewar, it willbe usable in all the places that our current Tektronix 2048 x 2048 is used. Following the successfulcompletion of the mini-mosaic, a full-size mosaic will be built, with the added complications of a largemechanical interface and the necessity for a very fast data system. If such an approach proves intractable,an alternate design to produce a 2 x 2 array of Tektronix 2048 x 2048 CCDs (24 um pixels) will beattempted.

The proposed mosaic will fit comfortably in the field of the triplet corrector, although modification maybe required to improve the images at large radii.The design will also allow the mosaic to be used at CTIOwith their new correaor. Based on funding, either one or two identical large mosaic imagers will be built,making this project a NOAO cooperative effort. The mosaic developed for the 4-m prime focus could alsobe used at the R-C focus to provide a 13-15 arcmin field with higher spatial resolution.

The data rate and data storage requirements are challenging and represent a significant advance over ourcurrent capabilities; CCDs are now read out at a 20 kilopixel/sec rate. This translates into 210 seconds toread a 2048 x 2048 CCD. For the mosaic made of sixteen 2048 x 2048 Ford chips, sequential readoutwould require almost an hour! If we were to increase the pixel rate to 50 kilopixels/sec and multiplex allsixteen readouts, we could read out the entire mosaic in 84 seconds. A bandwidth throughout the systemof 1.6 Mb/sec would be required. The storage of data represents another area where image sizes and pixelrates will tax the conventional approach in an unacceptable way. Each readout of the full mosaic yields128 Mb of data. A single Exabyte drive will require almost 11 minutes to write the data from a singleimage to tape. Seventeen such mosaic images will fit on a single 120 minute (2.2 Gb) video cassette.

Because such a major project will monopolize the available resources for a number of years, the projectwill run in two phases. During FY 1992, an attempt is being made to construa two "mini-mosaics". Thesewill permit an assessment of the technology and its extension to a larger imager. At the completion of themini-mosaics, an impartial review will be held to ensure that the technical issues have been properlyaddressed. A positive review from the panel and IPAC will mark the starting point for the project, whichis anticipated to take two additional years at the current level of support

The CCD Development ProgramTheacquisition, characterization, evaluation, and implementation of new CCD detectors will remain a highpriority, since all other aspects of our instrumentation program depend on our detectors. Two programsare being actively pursued to produce a substantial supply of large-format CCDs. One is a collaborativeeffort with Steward Observatory to use the CCD foundry at Ford Aerospace to produce custom devices,especially small-pixel rectangular formats for spectroscopic use. Thepackaging and thinning will be doneat Steward, with devices distributed to CTIO, KPNO, and Steward. The other route is through involvementby KPNO in the NASA-funded Space Telescope Imaging Spectrograph (STIS) development A test andcharacterization program is being carried out on Tektronix and SAIC/Ford 2048 x 2048 CCDs. Loanagreements with the STIS program allow visitor use of good devices at both CTIO and KPNO.

The long-term development effort will focus on detectors for the imaging mosaic. The goal is to createan imaging surface with 98% filling faaor. This would require a front, rather than side, orientation forthe lead bonding. The mounting surface would then be tapped with matching holes filled with conductiveepoxy, allowing the connections to be made underneath or at the side of the entire mosaic. This new

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architecture will require development and testing of new masks and characterization of the performanceof closely packed devices; the intermediate step will be a 4096 x 4096 mini-mosaic of 2 x 2 Ford CCDswith a similar buttable architecture.

Data Acquisition and CCD ControlThe associated CCD hardware (controllers, displays, etc.) must be upgraded to handle the new, largeformat low noise deteaors with four quadrant readout In FY 1992, we plan to complete one newgeneration controller based on the CTIO design. A steady effortof buying andassembling the componentsuntil every focal station has dedicated controllers with adequate capability is scheduled in the long-termplan.

The telescope and computer environment for data acquisition and reductions is a third area to whichKPNO will devote effort. The flow of information to the observer needs to be streamlined throughimproved and more interactive acquisition and quick look software (i.e., standard star magnitudes,transformation coefficients, automatic chip formatting for standard star observations, etc.). In FY 1991,we adopted ICE, an IRAF based data acquisition program, to replace our Forth based LSI-11 systems.More work is required now on optimizing this package and the associated routines for observingprocedures at Kitt Peak. For the longer term, an effort has been initiated to define the requirements forthe system that will eventually replace ICE. It is hoped that a system can be designed to run both opticaland IR deteaors.

Fiber Optics R&D ProgramFiberoptic spectroscopy offers a substantial increase in observing efficiency. In FY 1993, we willcontinueexamination of end treatments and connectors with respea to focal ratio degradation, scrambling, andoverall throughput We will also investigate techniques for guiding with fibers for use with the WIYNTelescope. For the 8-m program, we will develop a tiltable gripper and learn to deal with the very largefocal surface of the 8-m telescopes. We plan to maintain the same level of effort in fiber opticsdevelopment during the five year period of this plan.

c. 3.5-m Mirror Project

In March 1989, NOAO received the second 3.5-m diameter borosilicate honeycomb mirror castingproduced by the Steward Observatory Mirror Laboratory (SOML). The NOAO mirror blank was used totest the methods needed for producing high quality 8-m mirrors. This program involved developingtechniques for polishing, supporting, and thermally stabilizing the mirror that would reduce the individualerror sources (i.e., residual polishing error, support effects, thermal warpage, mirror seeing, etc.) to lessthan about 0.05 arcsec FWHM.

In October 1991, the Advanced Optical Technology for Telescopes (AOTT) Program was renamed the3.5-m Mirror Project The new name reflects remaining tasks.

3.5-m Mirror Project Major Milestones

March 1992 Complete prototype mirror cell, active support system, and thermal control system testsMay 1993 Finish aspheric polishingNovember 1993 Ship mirror and cell to WIYN site

In 1994, after completion of work on the 3.5-m mirror, this engineering group will again start looking atadvanced concepts for future telescopes. The major focus will be to develop specifications and conceptsfor a distributed array of optical/infrared telescopes.

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III. SOLAR ASTRONOMY

A. Science at NSO

The study of the nearest star continues to advance our knowledge of its structure and evolution, but ourunderstanding of the Sun is far from complete. Current research programs are investigating the internaldynamics of the Sun and exploring the structure of its photosphere and upper atmosphere.

1. Internal Dynamics

One of the most active areas of solar research is that of helioseismology, which uses acoustic waves toinfer the interior structure of the Sun. The objectives and program of the Global Oscillation NetworkGroup (GONG) are described elsewhere in this Plan, but other programs in helioseismology are also beingcarried out While the GONG projea is the primary path by which NSO is probing the solar interior, thereare several other programs whose aims include the use of the oscillations to probe the subsurface structureof magnetically active regions, the mapping of flows in the upper convection zone, and the study of solarcycle changes in the properties of the oscillations.

Observations obtained at the Vacuum Telescope on Kitt Peak have shown that sunspots absorb asignificant fraction (up to 50 percent) of incident p-mode acoustic wave energy. In addition, small sunspots(pores) and areas of enhanced magnetic activity (plage) also exhibit appreciable absorption. Observationsobtained with the Vacuum Tower Telescope at Sacramento Peak suggest that the absorption of theoscillation energy by a sunspot disappears while a flare is occurring. The absorption of acoustic wavesby sunspots and the possible emission of waves by flares hold out the hope of studying the subsurfacestructure of sunspots and active regions by a form of acoustic tomography. Currently, a number oftheoretical groups are working to uncover the mechanism causing the absorption effect Once this and theemission problem are solved, we will be able to study the evolution of solar active regions from a three-dimensional point of view. NSO plans to observe oscillations over the next five years during the decliningphase of the magnetic activity cycle. During this time, the effect of solar flares on the oscillations will bestudied, and more statistics on the interaction of the p-modes with sunspots will be obtained. Thesephenomena will be observed through the use of the spectromagnetograph and High-/ Helioseismographat the Vacuum Telescope on Kitt Peak.

In addition to the absorption and emission of p-mode oscillations by active regions, the oscillations maybe used to probe the horizontal velocity fields below active regions. Recently, a three-dimensional analysisof oscillation data has been developed in which the signature of the oscillations is a set of trumpet-shapedsurfaces in the kx - ky - v volume. When the surfaces are sliced at a constant temporal frequency (v), aset of rings appears. The central positions of these rings are proportional to an average over depth of thehorizontal components of the velocity of the solar plasma. By analyzing rings from data obtained atdifferent heliocentric positions, the horizontal flows can be determined inside and outside active regions.Observations from the Vacuum Tower Telescope at Sac Peak show that the presence of an active regionproduces a 20 m/s difference in both meridional and rotational velocities. With the aid of inverse theory,we can determine maps of the horizontal velocities as a function of depth beneath active regions. Thesemaps should be of great value in the study of the evolution of active regions. Coupled with a tomographicdetermination of the subsurface magnetic field structure, a three-dimensional picture of active regions willemerge.

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The ring diagrams can also be used to map the global pattern of convection in the Sun. A mosaic of ringdiagrams covering the solar disk will help to determine whether the largest scales of cells in theconvection zone are zonal, seaoral, or tesseral. Synoptic observations obtained with the High-/Helioseismograph over the course of a solarcycle will be essential to build up the statistics that are neededto answer this question and to determine if the cell shapes evolve with the solar cycle. Studies of flowsassociated with active longitudescan also be made, and the possibility that the formation of active regionsis presaged by a certain flow pattern in the convection zone holdsout the hope that a long-range forecastfor specific solar activity may be in reach.

While the existence of the solar cycle has been known for a century, its origin is still not understood. Themost developed explanation is dynamo theory which, until recently, was observationally constrainedmainly by the solar cycle period and the structure of the butterfly diagram. The results of helioseismologyhave shown that the interior rotation rate is not constant on cylinders as some numerical convention zonemodels had prediaed. As a consequence, some theorists have hypothesized that the seat of the solar cycleis at the base of the convection zone. However, the precision of current determinations of the solaroscillation spectrum is still too poor to distinguish between some very different patterns of the interiorrotation rate. The observational programs that NSO will undertake in the next five years will provideinformation that will be of great importance to dynamo models. New observations to be obtained at theSouth Pole will be compared with previous South Pole data to analyze solar cycle changes in thefrequencies and line widths of the modes, as well as the internal rotation rate. GONG will provide themost accurate determination of the internal rotation rate ever obtained. The High-/ Helioseismograph willyield maps of the horizontal flows as a function of both depth and longitude in the convection zone. Thisinstrument will also monitor the high-degree modes throughout the cycle, providing additional informationabout changes immediately below the photosphere. Solar interior tomography will allow the subsurfaceevolution of active regions to be followed. These prospective observations are exciting, as they willprovide unprecedented calibration for dynamo theory. Such observational advances must be accompaniedby corresponding theoretical progress in order to increase our understanding of the solar cycle.

2. Magneto-Convection

In a cool star like the Sun, energy is transported by convection in a thick shell that lies just below theradiative photosphere. Two convective eddy sizes have been recognized for decades: the granulation, withtypical sizes of 1500 km (2 arcsec), and the supergranulation, with sizes around 30000 km and lifetimesof approximately a day. Only recently, advanced observing and analysis techniques (developed at NSOand at Lockheed Palo Alto Research Labs) have confirmed the existence of a third scale~themesogranulation, with typical sizes of 7000 km. Theorists in the US and Denmark are engaged inmodeling the dynamic behavior of the turbulent, compressible, radiating flows that are involved in stellarconvection, and they use observations obtained at NSO and elsewhere (especially from La Palma) to guidetheir models. The models have advanced to the point where they give realistic representations of the time-evolution of solar granulation.

However, recent observations at NSO have revealed a previously undetected feature of stellar convectivemotions: the existence of rising and falling "plumes" of gas, distributed randomly over the photosphereand occupying a small fraction of the surface. These plumes are well-known in terrestrial hydrodynamicsystems (e.g. the ocean, and the atmosphere), and have recendy appeared in some solar simulations.

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Convection in the Sun has two important side effects. First, the turbulent motions produce sonic noise,which propagates into the overlying atmosphere, produces shock waves, and heats the low chromosphere.Gravity waves are also predicted above the convection zone, but their wavelengths are too short to bedetected direcdy, except for their role in broadening photospheric line profiles. Recent work at NSO isdireaed at estimating the energy flux in such gravity waves from high-spatial resolution observations ofgranulation. Secondly, convective motions transport magnetic fields that emerge from the solar interior.In the photosphere, these fields have kilogauss strength and occupy only a tiny fraction (-10^) of thesurface area.

The horizontal convective motions in the photosphere twist and braid the magnetic field loops that extendinto the corona. According to a plausible theory, the complex coronal field develops current sheets inwhich free magnetic energy is released to heat the corona. One of the prime objectives for observationalsolar astronomers, in the coming five years, is to test this idea. Vector magnetic field measurements inthe photosphere, at high spatial resolution, and fast imaging spectroscopy of the solar corona will berequired. NSO is developing the equipment needed to pursue these crucial investigations.

In active regions, convective motions twist the strong magnetic fields and convert kinetic energy to storedmagnetic energy. By processes that are still far from being understood, this free energy is released anddissipated in violent "flare" events. The present models of dissipation invoke electrical current sheets withtiny widths (one to hundreds of meters) in which anomalous electrical resistivity (produced by a varietyof current-driven waves) acts to thermalize the stored magnetic energy. In order to test these ideas,observations (at sub-arcsec spatial resolution) of vector magnetic fields, velocity fields, and temperatureand density structures in active regions will be required. NSO is developing a new generation of focalplane instruments to support these studies.

The NSO program to investigate magneto-convection begins with studies of the evolution and motion ofgranules in the photosphere. As a small convective cell, a granule appears as a bright upwelling of hot gasinto the stable overlying radiative layer. Analyzing the time development of this "overshoot" poses asevere challenge for the observer, since the density, temperature, and velocity of the granule must bemapped with sub-arcsec resolution. The appearance of new granules coincides with the displacement, againon sub-arcsec scales, of the kilogauss magnetic field points in the neighboring photosphere. The interactionof velocity and magnetic field produces MHD waves that can propagate to transport non-thermal energyto the low chromosphere. In sunspots, where the magnetic field is especially strong, these wave motionsare particularly visible. Further study of the generation of MHD waves will be pursued in the comingyears.

Simultaneously with the appearance of new convective cells, magnetic flux emerges from the underlyingconvection zone in the form of tiny, strong dipoles. The evolution, transport, merging, and decay of theseelementary structures are fundamental processes in the magnetic activity of the Sun which will requiremuch detailed study for a full understanding.

In active regions, the magnetic flux accumulates and is distorted by persistent shearing and twistingconvective motions. The processes of magnetic energy storage (as a system of stable electrical currents),and the impulsive dissipation of this system, are fundamental to the flare phenomenon. In collaborationwith scientists of the USAF Phillips Lab and visitors, NSO staff will participate in the detailedinvestigation of these processes using the advanced equipment now under development or recentlycompleted.

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Since all of the relevantprocessesmentioned above take place on sub-arcsecscales, high spatial resolutionis an essential requirement for any observational program. NSO has undertaken, therefore, a project todevelop adaptive optics for the Vacuum TowerTelescope at Sunspot This projea will result in the abilityto remove, instantaneously, the distortions to the solar image that are produced by the Earth's atmosphereand deliver a nearly diffraction-limited image to the analyzing instruments (spectrographs, filters,polarimeters, etc.) The task is extremely difficult, but is progressing as quickly as the current supportallows.

The small-scale dynamics of the chromosphere, prominences, and corona appear to be controlled bymagnetic flux tubes driven by photospheric motions. Observations from space (e.g. SMM, HRTS, rocketflights) have given tantalizing glimpses of the complex behavior of the plasma and fields in the upperatmosphere, but improved understanding of the physical processes involved requires more regularobservations at high spatial resolution.

Space platforms will eventually provide the ultimate in spatial resolution of the Sun. However,observations at the highest possible resolution from space are still years in the future. In addition toallowing many critical experiments, a well-conceived, long-term program of high-resolution solarobservations from the ground is an important predecessor and partner for any space program. Groundobservations serve to frame incisive questions for space experiments, to develop plasma diagnostictechniques, and to provide the time history of the solar magnetic cycle that is necessary to place the spaceexperiments into proper perspective. During the operational period of a high-resolution solar spacemission, NSO can play a critical complementary role, as was demonstrated with Skylab, Orbiting SolarObservatory-8, and the Solar Maximum Mission. NSO intends to play an active role in coordinatinggroundbased observations during the flights of Yokoh, Koronas, and SOHO, and it will continue toprovide support for rocketand balloon-borne experiments. In addition, NSO will work withthe communityto build toward a large aperture solar telescope in space later in the decade.

The NSO program to achieve high spatial resolution imaging of the Sun includes the development ofobserving techniques, including speckle and active optics reconstruction of solar images; development oftechniques to compensate telescope polarization using Liquid Crystal Devices to improve measurementsof vector magnetic fields on the Sun; and development of flare prediction algorithms based on therelationships between vector magnetic fields, chromospheric geometry, and observed flare locations andmagnitudes. Planned programs include observations and modeling of the effects of magnetic fields onenergy transport to provide data on the storage and release mechanisms that control solar activity; analysisof the transition in the solar atmosphere from convective and radiative (photosphere) to wave and radiative(chromosphere) energy transport and heating, by means of the recently developed correlation trackersystem used in conjunction with agile (rapidly tiltable) mirrors to stabilize the solar image; and use of verynarrow band filter systems (20 mA bandpass) to observe the height dependence of convective overshootand the concentration of magnetic flux tubes into larger structures.

NSO plans to augment the focal plane instruments at the Vacuum Tower Telescope (VTT) at Sac Peakfor high-resolution imaging and spectroscopy of the solar chromosphere. In collaboration with the HighAltitude Observatory (HAO), an Advanced Stokes Polarimeter is being developed for use at the VTT forstudies of the build-up and release of magnetic energy in flares, for research on the dynamics of spiculesand on MHD wave phenomena in sunspots, and for many other projects.

Infrared observations offer unique advantages for probing the magnetic and thermal structure of the solaratmosphere. For example, because the splitting of spectral lines in the presence of a magnetic field

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increases directly as the square of the wavelength, it is possible in the infrared to measure the intrinsicstrength and orientationof solar magnetic fields with a sensitivity that is difficult or impossible to achievein the visible region. The discovery at NSO of numerous atomic emission lines near 12 um has made thispossibility a reality, but the work of exploiting these lines has just begun. The vibration-rotation bandsof carbon monoxide (CO) at 2.3 and 4.6 um are a sensitive thermometer that can be used to probetemperature inhomogeneities in the upper photosphere directly and to test the validity of widely-usedatmospheric models. Moreover, the CO lines show prominent intensity oscillations that can be used tostudy the penetration of solar p-modes into the upper atmosphere. The infrared continuum is also avaluable diagnostic. The 1.6 um continuum arises deeper in the solar atmosphere than any otherobservable wavelength and provides a unique window on magnetic fields and convection below thephotosphere. Because the infrared continuum approximates the Rayleigh-Jeans portion of a blackbodycurve (with intensity direoly proportional to temperature), it is straightforward to study temperaturevariations both vertically and laterally.

Foryears, infrared observers struggled withsingle-element detectors while arraydetectors changed the faceof optical astronomy. The era of infrared arrays has now arrived, and their revolutionary effea has alreadybeen felt. A small-format (58 x 62) array for the 1-5 um region has been successfully used at the McMathTelescope during the last year, and large-format (256 x 256) infrared detectors are currently undergoingtests at NOAO.

The McMath Telescope is particularly well-suited to solar infrared observations. Its all-reflecting opticsprovide high transmission, low scattering, and low instrumental polarization at all infrared wavelengthsaccessible to ground-based observation. Its large aperture is a major advantage both for angular resolution(0.25 arcsec at 1.6 um, less than 2 arcsec at 10 um) and for lightgathering power (the number of solarphotons per Dopplerline-width is some 20 times smallerat 10 um than at 0.5 um). The scientific potentialand emerging technical capabilities have stimulated broad interest in an enhanced solar infrared facility.Studies indicate that an upgrade of the McMath to 4-m aperture is feasible and would be a cost effectiveway to respond to this need.

A new era in coronal and prominence studies is dawning at NSO, due to several technological advancesduring the past decade. The application of diode array deteaors and video cameras to coronal emissionlinespectroscopy, forexample, permits moreaccurate subtraction of the sky background, shorterexposures(because of the higher quantumefficiencyof solid state detectors),and much greater flexibility in real timeor post-observational image processing. As a result it has recently become possible to record accurateemission line profiles in coronal holes at intensity levels below a millionth of the disk brightness. Thisachievement opens the prospea of detailed studies of the physical parameters of coronal holes fromground-based telescopes, with important implications for solar and solar-terrestrial physics.

The importance of small-scale structures in the corona (with scales of a few arcsec or less) has beenemphasized recently, bothby observational andtheoretical studies. The heating of thecorona, forexample,has beenpostulated to occur througha continuous process of magnetic field reconnection. The freeenergycontained in the coronal field is thought sufficient to maintain the corona's high temperature. If thisprocess occurs, it must take place at small spatial scales. Evidence for such field reconnection, withassociated heating, has recently beenobtained at NSO with the 20-cm coronagraph. Further observationsand study of this process and others like it will be pursued vigorously with this and with futureinstruments, such as a large-aperture, fully-reflecting coronagraph.

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We are still close to the maximum of the current solar activity cycle. NSO's plans for coordinated flareresearch as partof the "Max '91" program suffered a major setback with the collapse of NSF support forthis program. However, with existing instrumentation and support from other agencies, NSO will continueto provide users with facilities for flare observations as a part of regular visiting scientist support. Forexample, the process of magnetic energy build-up in pre-flaring active regions can be followed with themulti-channel magnetograph on KittPeak and with imaging spectroscopy at Sac Peak. Ground-based flareobservations, taken in coordination with rocket, balloon, and Yokoh experiments, will continue to provideusers with the best available data on the impulsive energy release process in flares.

B. Initiatives for NSO

NSO has planned a series of initiatives designed to provide the new typesof observing facilities requiredto address the scientific problems outlined in the preceding section. GONG is the first of these programsto be funded, and fabrication of the instrumentation for the field stations is in progress. The key newinitiative within NSO during the coming decade is the construction, with international partners, of a newfacility for high-resolution studies of the Sua There is, in addition, wide-spread interest in developing anew solar infrared facility, which could also provide a capability for synoptic observations of the analogof solar activity in other stars, and in building a large all-refleaing coronagraph.

1. Global Oscillation Network Group (GONG) Project

The Global Oscillation Network Group (GONG) is an international projea to study the internal structureand dynamics of the closest star by measuring resonating waves that penetrate throughout the solarinterior~a technique known as helioseismology. To overcome the limitations of current observationsimposed by the day-night cycle at a single observatory, GONG is developing a six-station network ofsensitive and stable solar velocity mappers located around the Earth to obtain nearly continuousobservations of the "five-minute" oscillations, as well as direct measurements of the "steady" motions ofthe solar surface itself. To accomplish its objectives, GONG is also establishing a distributed datareduction and analysis system to facilitate a coordinated analysis of these data. The primary analysis willbe carried out by a dozen or so teams, each focusing on a specific category or problem. Membership inthese teamsis open to all qualified researchers; there are currently 119members, representing 50 differentinstitutions.

Milestones for the remainder of the projea are as follows:

GONG Milestones

October 1992 System Design ReviewOctober 1992 Data Reduction and Analysis Hardware OrderedJuly 1993 Data Reduction and Analysis Center OperationalSeptember 1993 Deployment Readiness ReviewDecember 1993 Network Deployment BeginsJune 1994 Network Operations BeginJune 1997 End Observations

June 1998 End Data Reduction

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Historical PerspectiveIn the early 1980s, a flow of exciting new results demonstrated the growing number of crucial questionsthat helioseismology could address: stellar internal rotation and oblateness, the neutrino deficit, and theefficiency of convection. At the same time, the limitations of observations from a single site, or from therelatively brief campaigns at the South Pole, werebecoming more and more apparent. Pressure to achievelong, continuous observations was mounting. In April 1984, NSO sponsored a workshop to explore thescientific questions and to investigate the technical issues. As a result of the interest and supportmanifested at the workshop, NSO staff, in collaboration with the scientific community, established GONGto coordinate efforts toward the design, construction, and utilization of a network of stations, distributedin longitude and dedicated to obtaining a uniform set of data. A proposal was generated and submittedto NSF in late 1984 by NSO on behalf of the entire scientific community.

In FY 1985, an examination of worldwide climatic data was undertaken to identify potential sites.Simulations that allowed for equipment failures and weather history from suitably located observatoriesindicated that a minimum of six sites, spaced roughly equally in longitude, would be required to achievethe design objective~a minimum of three years of nearly unbroken data. A robust, automated, digitalsunshine monitor for a survey of candidate sites was developed. Alternative technologies for making thesolar velocity measurements of the requisite precision were investigated, and the nature of the overallinvestigation began to take shape.

In FY 1986, an interim technology development program led to the design of a variable-path-lengthMichelson interferometer, with a narrow prefilter isolating a single solar line, to provide a stable andsensitive velocity measurement. Early in the year, the site survey, which grew to include 14 locations,started operation. The final sites, which were selected in April 1991, will be Big Bear Solar Observatory,Mauna Loa Solar Observatory, Learmonth Solar Observatory, Udaipur Solar Observatory, Observatoriodel Tiede, and Cerro Tololo Inter-American Observatory. Urumqi Astronomical Station is still beingconsidered as a possible seventh site.

The project obtained approval from the NSF in FY 1987 and produced first light on a full scale prototypeinstrument in March 1990. Major peer reviews of the GONG instrument, reduction and analysis softwaresystem, and the overall projea were conducted during the winter of 1990. Results from the site surveyindicate that we may anticipate observing duty cycles well in excess of 90 percent.

The Instrument

The five-minute oscillation is a subtle effect. Individual modes exhibit velocities of less than 20 cm/s,

while the sum of all the modes is only a few hundred m/s. The ultimate intention is to have themeasurements be limited by the "random" surface motions of the Sun. This goal requires the developmentof six stable instruments capable of making imaged velocity measurements with a precision of significantlybetter than 1 m/s.

The basic idea is to isolate a single solar absorption line and determine its precise (Doppler-shifted)wavelength. The instrument chosen for this task is called a Fourier Tachometer, similar to the onedeveloped in collaboration with the High Altitude Observatory. Based on a Michelson interferometer, itprocesses the light from all parts of the solar disk simultaneously to produce a velocity-sensitive imageof the Sun. This image is recorded by a 256 x 256 pixel solid-state deteaor and stored in the memory ofa data acquisition computer.

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At the conclusion of each sixty iecond acquisition cycle, three intensity images, differing in modulationphase by 120°, are summed, differenced, and divided to produce a single velocity image, as well as anintensity and a line strength image. The resulting velocity image is then stored on a magnetic tapecartridge, along with an intensity image and other information, for subsequent reduction at the central datareduction and analysis facility.

The entire field instrument will reside in an environmentally controlled shelter building, which will alsohouse an external light feed, Fourier Tachometer, control and acquisition computers, and data recordingequipment.

The light feed itself will be a fully automatic system, which will turn itself on each day, locate and trackthe Sun, continue to track using an ephemeris during cloudy periods, and supervise and report itsenvironment and operational status. Adaptive software is being developed that will create a real worldephemeris for the actual site and conditions as deviations from the "pre-canned" ephemeris are noted.

Data Management and AnalysisThe real challenge in the area of GONG data reduction and analysis is presented by two factors: (1) amonumental volume of data; and (2) a long sequence of complex computing tasks. Each station in thenetwork will produce at least 200 megabytes of data every day. The whole network will generate agigabyte a day, seven days a week, for three years. Over this time the total accumulation of field data willexceed one terabyte. The reduction process itself is not trivial. Each individual 64 K pixel frame of eachstation must be adjusted, pixel by pixel, for a variety of instrumental, photometric, and geometric effects.Furthermore, the Doppler effect of the known motions of the Earth and the Sun also must be removed.As many as three adjacent GONG stations may observe simultaneously for periods of several hours. Thesedata must be merged into a single stream of the best frames attainable at each moment

Once these preliminary tasks are complete, several more computationally intensive reductions will beperformed. For example, the decomposition of the image data into time series of spherical harmoniccoefficients and their subsequent reduction to frequency spectra will be standard processes. Finally, theraw field data, the ultimate reduced data sets, and several intermediate stages must all be placed in long-term storage in computer-based archives using a combination of optical disks and rotary head tapes.Scientific analysis of the data will generally proceed from these archived data sets.

While researchers may choose to write their own specific analysis programs, the GONG projea and itsscientific teams are establishing a central users' library of contributed analysis software, which will beavailable for general use. This library will include the data access and display system as well as basicanalysis tools, which will be fully supported and highly transportable so researchers may pursue work fromtheir home institutions.

The central GONG computing facility will feature a powerful network of computers and mass-storagedevices. This system will both reduce the data and provide for its distribution to the community. Inaddition to performing routine data reduction tasks, this system will also be available for research by bothon-site visitors and by remote access.

Many of the GONG data management tasks are very similar to those of the Stanford/Lockheed SolarOscillations Investigation (SOI) experiment. This experiment will be launched on the NASA/ESA SOHOspacecraft in 1995. GONG is engaged in a major collaboration with the Stanford group to provide for jointdevelopment of reduction, distribution, and analysis software common to both projects.

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Current Status and Future Directions

The prototype instrument/field stationis undergoing evaluation and further development. During FY 1992,this effort will lead to a "production prototype" that will closely approximate the actual field stations. Asystem design review will precede acquisition of the final field station components. Integration of thesesystems in the six field stations will follow, with network operations scheduled to begin in June 1994.

The data reduction and analysis system is a major component of the program and is being developedconcurrently. Even before the installation of the network, data acquired during the validation of theprototype should provide the basis for important research. The design and construction of the neededsoftware tools will require the efforts of both the projea staff and many other members of the solarphysics community. The principal hardware for this system will be procured and installed in late 1992 andwill be in full operation by July 1993. Coordination with the scientific community continues to be assuredby regular consultation with a five-member Scientific AdvisoryCommittee, a quarterly newsletter, and anannual GONG meeting (with some 96 participants from nearly 40 institutions and 14 countries in 1991).

The GONG projea is slated to gather data for a minimum of three years. Full-scale data analysis activitieswill continue for at least one year beyond the end of the data gathering phase. If the results of thesestudies indicate a need, the continuation of data gathering for a longer fraction of the solar cycle remainsa possibility. In any case, beginning in the mid-1990s we can look forward to some truly excitingdevelopments in our understanding of our nearest star.

2. Large Earth-based Solar Telescope (LEST)

BackgroundIn order to provide a ground-based facility capable of studying fundamental astrophysical processes withthe detail that only the Sun allows, a consortium of nine nations is planning to build a 2.4-m solartelescope at a site with superb seeing. This Large Earth-based Solar Telescope (LEST) will provide highphoton flux and low instrumental polarization and will be equipped with adaptive optics to attain angularresolution approaching 0.1 arcsec on a regular basis. The telescope will cost approximately $46M, ofwhich the US share will be one-third.

Status

The conceptual design of the LEST was selected in 1984 and endorsed by the Scientific and TechnicalAdvisory Committee of LEST. Since then, more than 30 studies have been carried out confirming andelaborating the concept These studies include detailed optical design, mounting and tower analysis, windtunnel and helium tests, polarization analysis, and studies of focal plane instruments (including adaptiveoptics, polarimeters, spectrographs, and new technology filters). The detailed design was reviewed in thefall of 1990.

AURA and UCAR have joined as US represenutives to the LEST Foundation, the governing body forLEST. A Scientific and Technical Working Group has been established to coordinate US efforts. Thisgroup has endorsed the LEST management's decision to let a contract for the detailed design of thetelescope to the same group that designed the Nordic Optical Telescope. The design phase will extendthrough 1993 at a cost of $3M of which $2M is already available from member contributions.

Adaptive optics are expeaed to play a key role in enabling LEST to reach its full scientific potential.R. Smithson's ground-breaking experiments with a prototype adaptive mirror at NSO/Sacramento Peak

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have confirmed that substantial improvement of image quality is possible even with existing designs, butmore development is needed. The LEST consortium has agreed, therefore, to pursue a dual-track strategy:to design the telescope and to identify work packages, including adaptive optics, which will beimplemented by individual groups. NSO and HAO have submitted a separate proposal for the US shareof these activities (approximately $2.1M over three years).

Future Artivities

During the next five years, NSO proposes the following program:to continue to develop, test, and employ adaptive optics systems,to represent the US solar community interest in LEST,to seek, with HAO, the US share of construction funds,to play a leading role in the design and construction of focal plane instruments for LEST,to participate in developing the data processing, archiving, and distribution systems necessary for

LEST,

• to participate actively in the LEST Scientific and Technical Advisory Committee (NSO member:R. Dunn) and the US Scientific and Technical Working Group for LEST (NSO members: S. Keil,D. Rabin).

3. Upgrade of the McMath Telescope to a Four Meter Aperture ("The Big Mc")

Facility ConceptNSO has completed a technical feasibility study of converting the present 1.6-m aperture McMathTelescope to a 4-m aperture. The study concludes that, given the mirror technology which is nowavailable, it is possible to increase the aperture of the present McMath telescope to 4 m with minimalchanges in the existing building structure and instruments.

Scientific Goals

The solar panel of the Astronomy and Astrophysics Survey Committee recommended the establishmentof a major, ground-based facility for frontier investigations of the Sun in the relatively unexplored regimeof the solar infrared (1-20 um). For solar research of this kind, a large aperture is required to obtain fluxlevels and angular resolution comparable to those at visible wavelengths. At the wavelength of the 12 umatomic emission lines of Mg I, which permit sensitive measurements of magnetic field strength in the highphotosphere, a 4-m McMath Telescope would have a diffraction limit of 0.75 arcsec. Magnetic fields inthe low photosphere could be directly measured with Zeeman sensitive lines near the opacity minimumat 1.6 um. In general, the increased Zeeman splitting in the infrared and negligible mirror polarizationwould facilitate vector measurements of magnetic fields. Vibration-rotation bands of CO and othermolecules would be used to probe sunspots and the poorly understood temperature minimum.

While the principal scientific goals for an upgraded McMath concern observations of the Sun in theinfrared, the telescope would also serve as a valuable and unique facility for synoptic studies in solar-stellar physics. A 4-m aperture can extend the efforts to detect stellar oscillations, analogous to the solarfive-minute oscillation, to a probable limiting magnitude of V = 6-7 for observations by Dopplerspectroscopy. Therefore, solar-type stars characterized by ages in the range 1 to 5 billion years could beobserved. Stellar convection deduced from line asymmetry requires spectral resolutions of AAA = 1-2 x105 and S/N = 103. Such spectra could be acquired in an integration time of 1.5 hours for V = 8.5,

43

sufficient to reach solar-type stars in the Hyades and thereby extend the study of solar-like stars oversignificant evolutionary time scales.

The McMath Upgrade ConceptWe visualize the present 2-m heliostat being replaced by a 6-m cell held by a modified altitude-azimuthtracking system. A preliminary engineering study suggests that the 6-m light-feed be an all-aluminumtracking mirror made of a mosaic of solid welded segments. The mirror would be actively supported andpossibly liquid-cooled. A combination wind-fence and mirrorcoverwouldprovide weatherprotection. Weforesee remote operation of the altitude-azimuth feed by a single person, as is standard procedure for thepresent heliostat. The 4-m concave mirror would be of almost identical construction. Because it has a fixedorientation, its mount is simplified. The present performance of the telescope in the visible will not becompromised.

When the conceptual design and cost estimates are complete, NSO will work with the community toprepare a proposal for this projea. The primary instrumentation for the "Big Mc" is already underdevelopment for use in the current facility. In particular, NSO is actively developing the solar infraredprogram through the use of both NOAO infrared arrays and a new NSO IR array. In the area of solar-stellar studies, NSO is designing a new cross-dispersed echelle spectrograph system combined with a largeformat CCD. This spectrograph will serve as a model for the development of stellar spearographs thatsatisfy the demanding requirements of stellar seismology.

4. Advanced Reflecting Coronagraph (ARC)

The field of solar coronal physics has advanced to a point where many critical and fundamental questionsare posed, but observational answers are inaccessible due to inherent limitations of existinginstrumentation. Performance restrictions arise primarily from the properties of a singlet-objective lens asused in a conventional Lyot coronagraph. Aberrations of the objective can be corrected in the secondaryoptical system, but fundamental limitations remain that preclude carrying out many types of criticalcoronal studies. A mirror-objective coronagraph avoids such problems since the primary image isachromatic with a fixed location, and magnification is not a function of wavelength. Furthermore, largeapertures to achieve higher angular resolution and photon flux are achievable. An all-mirror system wouldallow extended spectral-range observations.

Major improvements in optical polishing and reflective coating techniques have allowed the productionof mirrors with scattering properties similar to, or even better, than super-polished singlet-objective lenses.A small prototype coronagraph based on a super-polished silicon-objective mirror (Mirror AdvancedCoronagraph, MAC I) has been constructed at NSO/SP and used successfully to obtain images of thegreen-line (Fe XIV 5303 A) corona, confirming this technology. In a joint program with the Institutd'Astrophysique de Paris, a second prototype reflecting coronagraph with a 15-cm-aperture objectivemirror has been construaed. For this, two objectives have been prepared at IAP, one of zerodur and theother of fused silica. The optical design of a 55-cm-aperture reflecting coronagraph (MAC HI) has beencompleted. This is a sophisticated design that with specialconstructionmaterials and advancedmechanicalengineering, should allow performance in terms of angular resolution and overall sensitivity far superiorto any existing coronagraph. With this more advancedinstrumentation, many outstanding and fundamentalproblems of astrophysics can be critically studied, such as the following:

44

• The earlier idea of acoustic heating by waves propagating from the photosphere has now beensubstantially discarded since propagation of these waves is inefficient and observed upper limits areinsufficient to heat the corona. Processes related to electric current dissipation or MHD wavegeneration and damping are now receiving more attention, but observations of small-scale dynamicalphenomena are needed to support and offer more development of these ideas.

• Flow and condensation of the coronal plasma are known to exist above active regions and aroundprominences. Flows are particularly impressive in the case of post-flare loops, where rapid evolutionis present. Condensation of the coronal plasma is often assumed to explain the formation ofprominences but has never been directly observed, perhaps because either very small-scale processesor very faint emission is involved.

• Small-scale explosive or impulsive events are believed to produce fast ejections that propagate alongthe open magnetic field lines of a coronal hole, producing the fast solar wind. However, no detailedobservations exist of the ejeaion process.

• Coronal mass ejections are observed propagating through the outer white-light corona. Relatively littleis known about the basic physics. For this problem, high-resolution images, spectra, and magnetic fieldmeasurements of the inner corona are required.

The third coronagraph, MAC III, will be used both as a research-quality coronagraph and also as a "proof-of-concept" for a much larger coronagraph, which would have applications to both solar corona and low-scattered-light solar disk studies, as well as to the investigation of faint emission associated with planetaryobjects, stellar systems, and other galactic and extragalactic objects.

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C. Instrumentation for NSO

Table 4

NSO Five-Year Instrumentation Plan Summary

FY 1993

Sacramento Peak

Adaptive optics1Hilltop automationImage digitizerReflecting coronagraph1Small spar integration

Total

Tucson/Kitt Peak

McMath infrared3Spectromagnetograph II2Solar stellar cross-dispersionVideo filtergraph24-m McMath upgradeFTS polarimeter upgrade

Total

FY 1994

Sacramento Peak

Adaptive optics1Mark II correlation tracker

Multiple apertureReflecting coronagraph1CCD implementation

Total

Tucson/Kitt Peak

McMath infrared

Solar-stellar cross disperserVideo filtergraph24-m McMath upgradeFTS polarimeter upgradeKPVT optics upgrade2

Total

46

Project Labor CapitalScientist (mm) ($K)

Dunn 30 45

Moore 9 10

Moore 9 20

Smartt 5

Moore/Dunn 5 10

58 85

Rabin 20 10

Jones 10

Giampapa 5 15

Jones 8

Livingston 10 50

Harvey 5 10

58 85

Dunn 25 40

Moore 5 15

Dunn 5 5

Smartt 15

Moore J6 J266 102

Rabin 20 27

Giampapa 10 15

Jones 10

Livingston 15 50

Harvey 6 10

Jones _566 102

FY 1995

Sacramento Peak

Adaptive optics1Multiple aperture telescopeReflecting coronagraphCCD implementation

Total

Tucson/Kitt Peak

McMath infrared

Solar-stellar cross disperser4-m McMath upgradeFTS polarimeter upgradeKPVT optics upgrade2KPVT guider upgrade2

Total

FY 1996

Sacramento Peak

Adaptive optics1Multiple aperture telescopeLarge reflecting coronagraph study1CCD implementation

Total

Tucson/Kitt Peak

McMath infrared

4-m McMath upgradeFull-disk light feed2Cryogenic echelleImaging FTS design4

Total

FY 1997

Sacramento Peak

Adaptive optics1Large reflecting coronagraph design1CCD implementationSecond Hilltop spar

Total

47

Dunn 20 40

Dunn 15 45

Smartt 17

Moore JZ _2869 113

Rabin 20 30

Giampapa 15 45

Livingston 10 28

Harvey 5 10

Jones 10

Jones _969 113

Dunn 20 50

Dunn 18 24

Smartt 15

Moore _20 _5073 124

Rabin 25 40

Livingston 15 45

Jones 15

Giampapa 10 39

Brault _873 124

Dunn 30 37

Smartt 15

Moore 17 30

Dunn J5 JO77 137

FY 1997

Tucson/Kitt Peak

McMath infrared

4-m McMath upgradeFull-disk light feed2Cryogenic echelle

iging FTotal

Imaging FTS design4

Carried out joindy with USAF/PLCarried out joindy with NASA/GSFCCarried out joindy with NASA/SR&TCarried out joindy with NASA Atmospheric

Rabin 25 45

Livingston 15 50

Jones 17

Giampapa 12 42

Brault 8

77 137

Science RequirementsStudy of the nearest star continues to yield important results about its structure and evolution withsignificance for astrophysics and solar-terrestrial physics, but most observed phenomena remain poorlyunderstood. Over the next ten years or so, the NSO Strategic Plan calls for two principal scientific foci:studies of the solar interior and studies of the interaction between solar magnetic fields and plasmas. Thus,proposed research programs coverthe internal structure anddynamics of the Sun, the originandevolutionof its magnetic field, its influence on the structure of the atmosphere, and related topics. The majorcomponents of the instrumentation program are designed to support these two areas of research.

Internal DynamicsOne of the most active areas of research is that of helioseismology, which uses acoustic waves to map theinterior structure of the Sun. Past and present efforts in helioseismology have revealed much about theinternal rotational characteristics of the Sun. The objectives and program of the Global OscillationNetworkGroup (GONG) are described in Section in of this plan, but other programs in helioseismologyare also being carried out at NSO. The Sac Peak Vacuum Tower Telescope and the Kitt Peak VacuumTelescope are both used by NSO visitors and staff in studies of the global oscillations of the Sun.

The High-/ Helioseismograph will obtain high quality observations of p-modes with high-degree andmedium-to-high frequency at the Vacuum Telescope on Kitt Peak. Previous observations of these modeshave been limited by poor determinations of the spatial wavelengths of the oscillations. The data from theHigh-/ Helioseismograph is complementary to that produced by the GONG project which has muchcoarser spatial resolution. The High-/ Helioseismograph will also serve as a pathfinder for the high-resolution Solar Oscillations Investigation (SOI) on board the SOHO spacecraft a projea in which NSOwill be playing a major role. The High-/ Helioseismograph, unlike either the GONG or the SOI, isintended to run synoptically throughout the solar cycle. In this way, scientists can study the evolution ofthe flows in the convection zone throughout the cycle. Studies will also be made of the absorption andemission of the p-modes by active regions. The development of this instrument is essentially complete.Operations began in late 1991.

The utility of the South Pole as a helioseismology observing site has been amply and frequentlydemonstrated since 1980 by NSO scientists and collaborators. Advantages include high altitude, anextremely clean sky, constant Sun elevation, and the possibility of nearly uninterrupted observations forperiods on the order of 100 hours. NSO has collaborated with Bartol Research Inst., NASA/GSFC, and

48

Photometries, Ltd. during three austral summers with successful results each time. Much helioseismologyremains to be done from the South Pole, especially in the area of solar cycle changes. As in the past, itis expeaed that future South Pole work will be supported by grants from the NSF Antarctic Program andother agencies.

Magneto-ConvectionThe NSO/NASA Spectromagnetograph will provide an advanced, two-dimensional deteaor and real-timedata processing system for the calibrated measurement of solarmagnetic andvelocity fields at the VacuumTelescope on Kitt Peak. Changes in line shape and line position will be well separated in the final datastream so that thermodynamic, velocity, and magnetic variations in space and time can be properlymeasured and compared. The Spectromagnetograph will thus become a powerful new tool for study ofsolar magnetohydrodynamics over temporal and spatial scales ranging from synoptic variations over thesolar cycle to impulsive, flare-related phenomena. Daily synoptic observations will also be made to buildup a record of persistent global velocities, such as differential rotation, giant cells, and torsionaloscillations. Operations began in mid-1991 with the retirement of the 512-channel magnetograph.

In collaboration with the AFSC/PL, NSO will analyze designs for an LCD Filter for high-resolution veaormagnetic field measurements at the Sac Peak Vacuum TowerTelescope (VTT) and for a filter system thatcould eventually form the foundation ofaSolar Synoptic Network. Anarrow-band filter system (a20 mAFabry-Perot in conjunction with the Universal Birefringent Filter) has been developed, in collaborationwith groups at Florence and Naples, for measuring velocity and fields as a function of height in thephotosphere. The High Altitude Observatory is developing a Stokesspectrograph to operate in conjunctionwith an NSO light-feed and polarization compensator at the VTT. The Air Force is also supporting thedevelopment of a veaor magnetograph by Johns Hopkins University/Applied Physics Laboratory for useat the Hilltop Dome.

In order to study the crucial physical processes of magnetic storage and release, spectroscopic andpolarimetricobservations with a spatial resolution of at least 0.3 arcsec, extending over a period of severalhours, are required. To meet this objective, NSO is developing a new adaptive optics system designed toovercome the strong distortions of solar images that are induced by turbulence in the Earth's atmosphere.The Bahcall Committee's decade review of the needs of astronomy made the development of adaptiveoptics its highest priority among recommended programsof moderatecost. The technologyand techniquesemployed in the NSO system can be applied to large nighttime telescopes and also the Large Earth-basedSolar Telescope (LEST). In this sense, the Adaptive Optics program is a testbed for technology applicablethroughout ground-based astronomy.

The NSO system has several components: (a) a wavefront sensor that is designed to track granulation, (b)an adaptive mirror that removes the distortions as quickly as they develop (~10"3 sec), and (c) a digitalphasing reconstructor system that calculates the required signal to the mirror using the sensor's signal asinput All three of these components have advanced significantly during the past two years, despite limitedresources for the projea.

The NSO system builds upon experience gained using the Lockheed Adaptive Mirror at the VacuumTower Telescope at NSO/SP. Recent work has demonstrated the remarkable improvement in image quality(approaching diffraction-limited performance) that the Lockheed system can produce on a sub-aperture ofthe VTT.

49

The NSO Adaptive Optics system is the centerpiece of a new collection of focal plane instruments thatwill be available at the VTT for high-resolution studies. For example, the High Altitude Observatory, incollaboration with NSO, has developed an Advanced Stokes Polarimeter, which will provide veaormagnetic field measurements of unprecedented quality. A new horizontal spectrograph and a new narrowband filtersystem have been installed to take advantage of the high-quality images at the VTT. These newinstrument combinations will be used to study magnetic energy storage and release, wave motions inkilogauss flux tubes, and themagnetohydrodynamics of sunspots and the active chromosphere, to citeonlya few examples.

NSO plans to take advantage of the large-aperture, all-reflecting optics of the McMath Telescope at KittPeak to develop new instrumentation that exploits the unique scientific potential of solar infraredobservations. This effort includes a study to examine the feasibility of increasing the McMath aperture to4 meters.

To realize the full potential of the McMathTelescope for infrared astronomy, it must be mated to modeminfrared detector packages and data systems. What follows is a schematic list of needed auxiliaryinstrumentation and some of the scientific capabilities it will provide.

• Near-infrared camera. Equipped with a 128 x 128 indium antimonide array, this instrument willprovide three new capabilities: 1) spectropolarimetry of Fe I 1.565 um for maps of magnetic fieldstrength; 2) direct imaging in the 1.63 um and 3.70 um continuum windows, reaching from 40 kmbelow to 40 km above the base of the photosphere; 3) area spectroscopy of the CO fundamentalvibration-rotation bands near 4.67 um to infer the lateral temperature structure of the temperatureminimum region. The camera will also accept one of the 256 x 256 platinum silicide arrays alreadypurchased by NOAO.

• 5 • 25 \un camera. This instrument would incorporate a 20 x 64 IBC array (now being tested atNOAO). It will provide 1) area spectroscopy and spectropolarimetry of the 12 um lines for analysisof magnetic flux tubes, and2) directimaging of the 11-um continuum window, probing 130 km abovethe base of the photosphere.

• Cooled spectral isolators beyond 2.5 um. For high-resolution spectroscopy it is important that onlya rathernarrow bandpass reach the deteaor so that undispersed background light does not overwhelmthedispersed solarsignal; similar considerations apply to Fouriertransform spectrometry. The spectralisolatoritselfmustbe cool.Depending on the application, a gratingspectrometer postdisperser, tunableFabry-Perot filter, or sets of narrow band interference filters might be preferred.

• Data systems with real time processing. In typical solar applications, low-noise infrared arrays willbe saturated in a fraction of a second. To build up the signal-to-noise ratios that will often be required,it will be necessary to average tens or hundreds of frames of data at each spectral/spatial location.There is a similar requirement in nighttime work, so the effort will be NOAO-wide.

Considerable interest has arisen in the ground-based monitoring of small solar irradiance fluctuations, forboth their astrophysical and solar terrestrial importance, and NSO is preparing to support a communityinitiative~SunRISE-to develop a specialized, precision solar photometric telescope to carry out thismonitoring. This initiative will include external funding for both labor and non-payroll costs.

50

Extended (full-day) observations with the existing coronal photometer on the Evans Solar Facility sparhave detected subtie transients in the emission-line corona. This discovery indicates the existence of apreviously unknown regime of frequent, low-level coronal aaivity. To investigate these transient eventssystematically, we need a dedicated coronagraph feed. Therefore, NSO will be recommissioning the sparecoronagraph as a dedicated feed for the Coronal Photometer.

The nature of the solar magnetic activity cycle is not understood, and much of the effort in this field goesinto long-term synoptic studies similar to those in the solar-stellar area. The aging colleaion of solarsynoptic telescopes currendy used to provide the bulk of the low-resolution synoptic observations shouldbe replaced by a standardized, research grade, worldwide network of small synoptic instruments to forma Solar Synoptic Network. There is considerable interest in this concept on the part of several governmentfunding agencies, and also in several other countries that support research in this area. NSO will continueto play a leadership role in the definition of this worldwide program, and these efforts may result in aseparate initiative, to be submitted primarily to agencies other than the NSF, in this area in the future.

Solar-Stellar

Several exciting and important areas in solar-stellar physics can be advantageously pursued in the infrared.In order to realize the potential in the infrared fully, an array deteaor must be installed at the McMathfor nighttime use. The detector may eventually be coupled with a cryogenic echelle spearograph, thusestablishing a uniquely powerful capability for solar-stellar synoptic spectroscopy. Illustrative examplesinclude stellar magnetic field measurements, where the direct dependence on wavelength of Zeemansplitting relative to thermal Doppler widths results in a higher sensitivity to complexes of magnetic activityon stellar surfaces. Spectroscopic signatures of cool star spot umbrae are more evident in the infrared dueto their increased brightness relative to the surrounding quiet photosphere. Exploratory programs in stellarseismology using CO line intensities could be pursued in the infrared. The near-infrared He I triplet featureat 10830 Ais a valuable proxy for coronal X-ray emission insolar-type stars. This line isnot within reachof our current CCD system, but a suitable IR deteaor would enable synoptic programs that emphasize thiskey diagnostic to be implemented.

Current capabilities in visible light spearoscopy will be enhanced to achieve a Doppler velocity precisionin the few meters per second range. The study of stellar convection requires resolving powers (k/Ak) of1.5 - 2x 105. Exploratory programs in stellar seismology and extra-solar planetary detection, each usingDoppler spearoscopy, demand the simultaneous acquisition of numerous spectral lines. The cross-dispersing of our echelle and the new slicer system represent significant steps toward increased spectralrange and enhanced spectral resolution for the McMath nighttime program. The addition of a gas cell inthe optical beam that would allow the superposition of reference features onto the stellar spectrum wouldincrease the precision that can be attained by providing a measure of spectrograph stability.

NSO would like to install a photometric capability in the form of an Automated Photometric Telescope(APT) to support the stellar spectroscopic programs at the McMath. The APTs are 1-meter class robotictelescopes that operate with minimal support The addition of photometry would be invaluable to programsinvolving the Doppler imaging of starspots and coordinated campaigns to study stellar flares. This couldbe a rum-key purchase when the opportunity presents itself.

In addition to the solar-stellar instrumentation that resides specifically at the McMath telescope, we aredeveloping a prototype of a wide-field K-line filter. The filter is intended for use at a large aperturefacility for the regular observation of solar-type stars in open clusters. The objective is to gather data oncycles in solar-like stars that are similar in age and chemical composition. The construction of the thermo-

51

mechanical filter enclosure is complete. We are awaiting shipment of the final optical elements, andcompletion is expected in 1992.

In addition to the major programs described above, NSO plans to modify and improve existinginstrumentation. Several of these projects are described in the following paragraphs.

McMath FTS Polarimeter UpgradeThe NSO Fourier Transform Spectrometer located at the McMath Telescope is a unique and very powerfulinstrument for studies of the solar spectrum. It was installed in 1975 and a few years later a polarimeterwas built as an accessory to obtain solar spectra in circular and one kind of linear polarization. Thispolarimeter has been very successful and much of what we know about solar magnetic fields can beattributed to this instrument. More could be learned with some modest upgrades. First is a mechanicalchange to permit calibration optics to be reproducibly placed in the beam. Some electronic changes wouldproduce a significandy higher signal-to-noise ratio. A change to the modulator assembly would improvebeam pointing stability. Adding a movable half-wave plate would allow all states of polarization to bemeasured efficiendy. A final, fairly major upgrade would be to add a zinc selenide modulator and suitabledeteaors to allow polarizations to be measured redward of the current 2.5 micron limit.

KPVT Video FiltergraphThis projea will provide a unique facility for observing solar chromospheric activity using the helium1083 nm absorption line. This line provides information on the state of the corona that is not revealed bythe other chromospheric lines observable from the ground. The instrument consists of a narrowband filterthat isolates the spectrum line and feeds an image to a television camera of the sort used in theSpectromagnetograph. Images are collected 60 times a second and accumulated and processed byvideo-rate hardware. The filtering has been designed so that intensity images will be obtained as thedifference between the spectrum line and the nearby continuum to obtain very high photometric sensitivity.Additionally, it is possible to make Doppler shift and Zeeman shift images. These capabilities add up toa powerful facility for studying energetic activity in the chromosphere. This projea is part of the jointNSO/NASA development plan for the NSO/Kitt Peak Vacuum Telescope and has received NASA funding.

KPVT Guider UpgradeThe guider for the NSO/Kitt Peak Vacuum Telescope was designed and built in 1973. It operates bylimb-sensing a small auxiliary image formed by much of the main optical system. In the early 1980s, amajor improvement was made by locking the main and guiding beams together via a laser driven servoloop. The present guider system contains obsolete electronics, does not operate well in some light leveland temperature conditions and does not operate under certain configurations of scanning speed and angle.These conditions mandate that an upgrade be made in order to avoid a sudden cessation of synoptic dataand to enable the telescope to be used under a wider range of observing conditions than at present.

KPVT Full-disk LightfeedThe NSO/Kitt Peak Vacuum Telescope was built in 1973 and was designed to be able to feed unimagedsunlight to auxiliary optics or directly to the focal plane instrumentation. This capability was notimplemented at construction time because of limited time and budget Completing the telescope by addingthis light feed would open a wide range of new observations and improve the quality of the existingobservations by permitting better calibrations.

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KPVT Optics UpgradeThe NSO Kitt Peak Vacuum Telescope is one of the largest solar telescopes in the world. It has a windowof 86-cm aperture and an image forming mirror of 70-cm aperture. The telescope was built in 1973 toprovide seeing-limited synoptic observations of the Sun's magnetic field and chromosphere. The focalplane instrumentation was built with one arc-sec sampling. Seventeen years of experience has shown thatthe image quality is often limited by this coarse sampling rather than intrinsic seeing on Kitt Peak. Newinstrumentation either built recendy or planned will permit finer sampling. Experience has also shown thatthe optics of the telescope are frequently a limiting factor in getting high angular resolution. Measurementsindicate that several of the optical components are not figured to contemporary quality standards.Additionally, the image forming mirror is mounted in such a way that it vibrates at about 30 Hz with anamplitude that may reach nearly one arc second. Remounting this mirror and refiguring the worst opticalelements will allow the Vacuum Telescope to do research projects that are now not possible.

McMath Imaging FTSThe Fourier Transform Spectrometer located at the McMath Telescope has proven to be a powerfulinstrument for the study of solar and laboratory spectra. It is one of NOAO's instrumental crown jewels.At the moment it uses only one detector. In the late 1970s it was used in an imaging mode to study thespectra of planets with several hundred simultaneous spatial points. Advances in CCD deteaors andreal-time data processing electronics now make it feasible to add an imaging capability for solar andlaboratory spectroscopy. This enhancement would be comparable to the advance of infrared astronomyexperienced when detector arrays replaced single detectors. For solar research it would be possible toproduce maps of solar features showing the run of physical parameters versus height from the base of thephotosphere through the upper chromosphere. For laboratory sources, different excitation conditions andresponses could be studied in lamps that employ localized geometries. The instrument would be at theforefront of modem detector and data handling technologies in order to cope with the vast amounts ofinformation provided by the Sun but now lost to existing instruments.

Hilltop AutomationThis projea is to integrate the complex of instruments currently mounted on the spar of the Hilltopfacility. Each of the seven instruments has individual, rather primitive, control systems of limited capacity.The proposed automation would provide the basic intelligence at the dome for programmable observingsequences and automated data acquisition The architecture would also be consistent with developmentsfor the Tower and Evans facilities, allowing remote control from these and other facilities.

Second Hilltop SparThe need of additional spar space for new instrumentation is apparent The current Hilltop spar isoverloaded to the point of tracking errors. Another spar would allow some of the heavier instruments tobe moved and the existing spar rebalanced. We also anticipate requests from the community to developand bring to Sacramento Peak small synoptic instruments. To support the community in this way, we willneed additional spar space to mount such instrumentation.

Small Spar IntegrationThis projea is seen as a cost effective, short-term solution to the overload stress currendy existing on theHilltop Spar. The idea is to refurbish the eight-foot spar in the Grain Bin Dome and use it for some ofthe smaller, less critical instruments. But the primary goal is to provide instrumentation mounts for thecommunity.

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Mark II Correlation Tracker

This projea is intended to capitalize on the parallel research efforts now underway concerning newcorrelation trackerdesigns. Various institutions are working currently on hardware implementations, PCversions, and VME-based versions for balloon flights. After several of these programs have reached areasonable state of completion, and based on their comparative performance, a consensual plan would bedeveloped to produce an advanced but technically simpler version of a correlation tracker.

Image DigitizationThe Image Digitization projea is to provide a comprehensive facility for film digitization. It will consistof the existing Fast Microphotometer in an upgraded form, a linear CCD array for digitizing film strips,a video camera and frame grabber, and perhaps other large-area arrays for high resolution work.

CCD ImplementationThis is seen as an ongoing effort by the Observatory to continue to provide state-of-the-art deteaors tothe community. Many existing instruments that are only film-based will need to have CCD capabilitiesadded. New instruments using CCD technology will have to be integrated into the existing systemarchitecture. The general advance of this technology also requires that we look continuously at newdeteaor designs and implement them when appropriate.

VTT Multiple-Aperture SystemThis project would create sixindependent light paths of reduced aperture forthe Vacuum Tower Telescope(VTT) on Sacramento Peak. Many experiments do not require the full aperture size of the VTT, andseveral experiments could be carried out simultaneously with such an arrangement. Further, underconditions of less-than-optimum seeing for the full aperture of the VTT, resolution would be superior inthe sub-aperture channels.

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IV. OBSERVATORY OPERATIONS

A. Cerro Tololo Inter-American Observatory

Overview of the Facilities

CTIO operates six telescopes with a range of capabilities chosen to accommodate the research needs ofUS astronomers in the Southern hemisphere. The multi-purpose 4-m telescope is still the largest opticaltelescope in the Southern hemisphere and has been equipped with the most modem instrumentation forimagingand spectroscopy. Coupled with the dark sky at Tololo, the 4-m telescope has been an importanttool in the study of the most distant galaxies and quasars. The 1.5-m telescope is also multi-purpose andis the optimal telescope for infrared observations at CTIO. It has been used extensively for infraredspectroscopy and imaging photometry and has produced excellent results for objects in the MagellanicClouds.

The 1-mand 0.9-m telescopes have been operated for several years now as dedicated facilities, performingthe tasks most requested by observers (i.e., imaging and spectroscopy). The Yale 1-m has been equippedwith a two-dimensional photon counting spectrophotometer, which has been used extensively to studysupernovae, active galaxies, and mass transfer binaries. In addition, a single-channel photometer ispermanently mounted on a side port of the 1-ra telescope, providing for rapid changes betweenspectroscopy and photometry. The 0.9-m is used exclusively for CCD imaging photometry.

The Michigan Curtis Schmidt is equipped for wide field photography and objective prism surveys. It hasbeen the workhorse of such pioneering investigations as the discovery of carbon stars near the galacticcenter and the search for distant QSOs. During FY 1990-1991,a CCD imaging capability for this telescopewas supported on a limited basis, andwe anticipate offering this facility again beginning in FY 1993 aftercompleting tests of the new array controllers. The smallest telescope, the Lowell 24-inch, is used forsingle-channel aperture photometry and has been active in establishing photometric sequences.

The full complement of telescopes and associated instrument configurations at CTIO are listed in Table 5.

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Table 5

CTIO Telescope/Instrument Combinations4-m Telescope:

ARGUS Fiber-fed Spectrograph + Blue Air Schmidt Camera + Reticon CCD [26]+ Red Air Schmidt Camera + GEC CCD [25, 26)

R-C Spectrograph + Blue Air Schmidt Camera + Reticon CCD [26]" " + Red Air Schmidt Camera + GEC CCD [25, 26]" " + Folded Schmidt Camera + Teka CCD [25, 26]

Echelle Spectrograph + Blue Air Schmidt Camera + Reticon CCD [26]it n + Red Air Schmidt Camera + GEC CCD [22, 25, 26]11 M + Long Cameras + TI, Tek* or Thomson CCD [23, 25, 26]

Prime Focus Camera + TI, Teka or Thomson CCDM II H + Photographic Plates [23]

Cass Direa + TI, Teka or Thomson CCD

" " + PtSi IR Imager (f/30 or f/7.5) [23, 27]Rutgers Imaging Fabry-Perot + TI or Teka CCD [25, 26]ASCAP Photometer [24, 25]IR Photometer (InSb and/or bolometer)IR Spectrometer + SBRC array [21, 22]IR SBRC Array Imager [21]

1.5-m Telescope:Cass Spectrograph + GEC CCD (with UV-Fluorescent Coating)Bench-mounted Echelle Spectrograph + Blue Air Schmidt Camera + Reticon CCD [22,23, 26]

" " + Red Air Schmidt Camera + GEC CCD [22, 23]+ 700 mm Camera + TI or Teka CCD [22, 23]

Cass Direa + TI, Teka or Thomson CCD" " + Photographic Plates [23]" " + PtSi IR Imager [23]

Rutgers Imaging Fabry-Perot + TI or Teka CCD [25]ASCAP Photometer [24, 25]IR Photometer (InSb and/or bolometer)

IR Spectrometer + SBRC array [21, 22]IR SBRC Array Imager [21]

1-m Telescope:Cass Spectrograph + 2D-FruttiASCAP Photometer [24, 25]Filar Micrometerb

0.9-m Telescope:Cass Direa + TI, Teka, or Thomson CCD

" " + PtSi IR Imager [23]Filar Micrometer1'

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0.6-m Telescope:ASCAP Photometer [24, 25]Filar Micrometer1'

Curtis Schmidt:

Photographic Plates (Direct or Prism)PtSi IR Imager [23, 27]TI, Tek4 or Thomson CCD (Direa or Prism Service Obs.)c [21, 22, 27]

* Numbers in boldface following an instrument indicate the most recent NOAO Newsletteris) containingrelevant articles. If there is no number, the 1990 edition of the KPNO Facilities Manual is fully up-to-date. The most recent general summary of CCD charaaeristics is in 23; also see subsequent issues,especially 26. Information on telescope control and guiders is in 21, 22, 24.

Tek CCDs available second semester one 512 x 512, 27 um pixels; two 1024 x 1024, 24 um pixels.Filar micrometer limited to long-term programs.CCD on Curtis Schmidt limited to service observing until second semester 1992.

Site SurveyThe Andean peaks of northern Chile have been shown to provide excellent Southern hemisphere observingsites, and both NOAO and other US institutions plan to place more large telescopes in Chile. Since thesummit of Tololo is now fully occupied, alternative locations must be explored. Fortunately, other peaksexist on AURA property that are already known from previous testing to be good telescope sites.

The highest peak on AURA land is Cerro Pachon (2,725 m). Cerro Pachon appears to be the best site foradditional NOAO telescopes, in particular, for the southern Gemini 8-m telescope. Cerro Pachon consistsof a ridge about 1.8 km long, on which several distinct summits are located. Its higher elevation is anadvantage for infrared observations. Tests in the 1960s indicated that the seeing was excellent There isample room for several telescopes, and the site is close enough to CTIO to make use of much of theexisting infrastructure.

Site testing of Pachon was begun in FY 1989 and will continue through FY 1993. A road has beenconstructed to the summit and a small cabin has been built to provide living quarters for the workermonitoring the survey equipment. Data are now being gathered daily by a weather station, microthermaltower, acoustical sounder, an IR water vapor monitor, and a 12-inch telescope used as a seeing monitor.The latter instrument was replaced late in FY 1991 by a copy of the seeing telescopes developed atLas Campanas Observatory, with a second copy to be installed during FY 1992 on Tololo. Themeasurements made with these telescopes will provide an accurate comparison of the two sites. They willalso help to tie in the Pachon results with those of the site surveys being carried out at the Las Campanasand European Southern Observatories. During FY 1992-1993, tests will be made on several of thesub-peaks of Pachon to determine if there are any significant differences in the seeing properties of theselocations.

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B. Kitt Peak National Observatory

Overview of the Facilities

The first of the AURA managed observatories was established at Kitt Peak, and telescopes at that site havebeen continuously in operation since 1959. KPNO now operates six nighttime telescopes. The 4-mtelescope is a general purpose telescope that is used in the optical and infrared for spectroscopy andimaging. The 2.1-m telescope is used for infrared imaging and spectroscopy, for low-resolution opticalspectrophotometry, CCD imaging, and coude" spectroscopy. The 1.3-m telescope is used for photometryduring dark time and, with its chopping secondary, is particularly well-suited to measurements of extendedobjects with low surface brightness. In bright time it is used for infrared astronomy. The Burrell Schmidtis the only nationally accessible Schmidt in the Northern hemisphere that is equipped with prisms andCCDs for imaging and spectroscopic surveys; this telescope is operated joindy by KPNO and CaseWestern Reserve. The Coude" Feed Telescope was designed to send light to the coude" spectrograph at the2.1-m telescope, thereby allowing use of the spectrograph when the 2.1-m is being scheduled for otherprograms. To help reduce costs and to make way for the new WIYN telescope, the #1 0.9-m was closedin the summer of 1990. This telescope has now been acquired by a consortium, the SoutheasternAssociation for Research in Astronomy, which plans to operate the telescope in a semiautomated mannerat a site located on Kitt Peak. The remaining 0.9-m now has three instruments: a single channelphotometer system, a direct CCD imaging system, and an intensified Reticon scanner forspectrophotometry.

Table 6 lists the Kitt Peak telescopes and summarizes the instrumentation available for each.

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Table 6

KPNO Telescope/Instrument Combinations

4-m TelescopePrime Focus Camera + Photographic Plates

+ Cass Direa CCD ImagingBench Spectrograph + "Hydra" Multi-Objea Fiber FeedR-C Spectrograph + CCD (UV Fast Camera)

+ Cryogenic CameraEchelle Spectrograph + CCD (UV Fast Camera)Infrared Imager (TRIM)Infrared Cryogenic Spectrometer (CRSP)Fourier Transform Spectrometer (InSb and Si)Multi-object Fiber-optic Feed (NESSIE)

2.1-m TelescopeGold Spearograph + CCD (Wynne CJ Camera)Cassegrain Direa CCD ImagingInfrared Imager (IRIM)Infrared Cryogenic Spectrometer (CRSP)Fiber Optic Echelle Spectrograph + CCD (Visitor Instrument)Coude" Spectrograph #5 or #6 Camera + CCD

Coude" Feed

Fiber Optic Echelle Spectrograph + CCD (Visitor Instrument)Coude" Spearograph #5 or #6 Camera + CCD

1.3-m TelescopeMark III Photometer

Infrared Photometer (OTTO 1-5 fm InSb Bolometer)Infrared Imager (IRIM)Infrared Cryogenic Spectrometer (CRSP)Infrared Simultaneous Four-Color Imaging Array (SQIID)

Burrell-Schmidt TelescopeDirea Photographic or choice of five objective prisms + Photographic Plates or CCD

0.9-m TelescopeAutomatic Fdter Photometer

White Spectrograph + Intensified Reticon ScannerDirea CCD

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Approximately 600 astronomers use KPNO telescopes each year. About twenty percent of the users arefrom institutions that have major telescopes of their own but wish to make use of unique instrumentationat KPNO. Each semester there are about twenty students carrying out observations for Ph.D. dissertations.

There are several other telescopes on Kitt Peak in addition to the KPNO nighttime facilities. NSOoperatesthe Vacuum Telescope, which provides much of the basic monitoring data for the Sun including dailymagnetograms, and the McMath, which is used for both solar observations and monitoring of stellaractivity. Othertelescopes areoperated by the National Radio Astronomy Observatory (NRAO), includingone of the antennas for the Very Long Baseline Array (VLBA) on the southwest ridge; by StewardObservatory of the University of Arizona; and by the MDM Observatory, which serves the University ofMichigan, Dartmouth College, and the Massachusetts Institute of Technology.

New TelescopesAs described elsewhere in this plan, a consortium comprised of the University of Wisconsin, IndianaUniversity, Yale University, and NOAO (WIYN) will construct and operate a 3.5-m telescope on KittPeak, which NOAO will use primarily for multiple-object spectroscopy.

Stimulated by theoretical calculations by R. Garstang (U. of Colorado) that show Kitt Peak should stillbe a good dark sky site, KPNO staff have undertaken a series of measurements of sky brightness. In theV magnitude, measurements demonstrate that Kitt Peak is only about 0.10 mag brighter than the valueexpeaed for a completely dark sky. Calculations by Garstang, based on predictions of population growthby the State of Arizona, suggest that by the year 2035 Kitt Peak will be only 0.26 mag brighter than thenatural sky background at the zenith. These calculations do not take into account the effea of the lightingordinances.

C. National Solar Observatory

The National Solar Observatory operates facilities on two sites, Sacramento Peak and Kitt Peak, for bothsolar and stellar astronomy. In addition, NSO has taken the lead in formulating and implementing theGONG projea, which is designed to probe the interior structureof the Sun by analyzing solar oscillations.NSO, in partnership with the High Altitude Observatory (HAO), is the US representative to the LESTFoundation, an international consortium to consider construction of the next generation, large ground-basedsolar telescope. The GONG and LEST projects are described elsewhere in this Long Range Plan.

The facilities operated by NSO play a unique role in solar astronomy in this country and indeed the world.The US solar community is largely dependent on NSO facilities for observational solar physics, and theyremain the largest and best instrumented anywhere in the world. In accepting this significant responsibility,NSO has forged important partnerships with major US solar research interests, such as the US Air ForceSystems Command Phillips Lab., NASA Goddard Spaceflight Center, NOAA Space EnvironmentLaboratory, and UCAR High Altitude Observatory, to support various aspects of these activities.

In concert with its several partners, NSO has developed a decadal Strategic Plan to guide the evolutionof its program and facilities. Scientifically, this plan places its major focus on two areas of study: the solarinterior, and the interaction between solar magnetic fields and plasmas. Operationally, the plan emphasizesthe fullest utilization of existing facilities through enhancements to their focal plane instrumentation andimprovements to their basic capabilities. Enhanced funding would allow the realization of major newfacilities, such as the expansion of the McMath Telescope to a 4-m aperture to provide a gready-enhanced

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IR capability, and a large-aperture reflecting coronagraph for advanced coronal and otherlow-scattered-light studies.

Overview of the Facilities

The Vacuum Tower Telescope (VTT) at Sac Peak consists of an evacuated reflecting telescope with a1.6-m diameter primary mirror (76-cm entrance window). It is designed to provide high spatial-resolutionimages and spectroscopy of the Sun. Primary analyzing instruments consist currently of a 12-m EchelleSpectrograph, a Universal Spectrograph, a Horizontal Spectrograph, a Universal Birefringent Filter plusa narrow-band Fabry-Perot Interferometer filter system, other specialized birefringent filters, an AdvancedStokes Polarimeter (with HAO), CCD cameras, and some small, specialized instruments. Horizontal andvertical optical benches are available at two exit ports for mounting temporary experiments.

The high-spatial resolution possible with the VTT enables important studies of fine details of the solaratmospheric structure, including prominences. Most experiments seek 1) high spatial and spectralresolution spectra, 2) high spatial-resolution, narrow-spectral-band images, or both. Quiet Sun studies areconcerned mostly with energy transport and atmospheric heating as produced by small and large-scaleconvection and wave motions in the photosphere and chromosphere. Small-scale, intense magnetic fieldsand associated velocity flows in the quiet Sun are an important area of research. The complex plasmaprocesses that charaaerize active regions remain poorly understood. In evolutionary terms they arecharacterized by flux emergence, adjustment of active region structure to rearrangement of thesubphotospheric field, and decay. The formation of sunspots and pores in active regions and theirmorphological characteristics continue to pose many fundamental questions in solar physics. Flareprocesses are even more complex, because of the rapid, localized release of large amounts of energy. Inthis area of research also, the magnetohydrodynamic complexities are such that considerable interpretiveuncertainties remain, and more research needs to be done.

The John W. Evans Solar Facility at Sacramento Peak has two 40-cm aperture emission-line coronagraphs,a 40-cm aperture telescope and other smaller telescopes mounted on an 8.2-m, photoelectrically-guidedspar, and a 30-cm coelostat. The main coronagraph and the coelostat are each designed to feed light toa variety of analyzing instruments, including a 13-m Littrow Spectrograph, a Spectroheliograph, aUniversal Spectrograph, and a Coronal Photometer. Array deteaors are available for spectrographs andimaging.

As with the Vacuum Tower Telescope, experiments carried out at the Evans Solar Facility cover a broadrange of solar phenomena. Emphasis is placedon observations of the emission corona, prominences, anddisk features, where the low-scattered-lightof a coronagraph is essential. Certain observations are routinelyrecorded on a daily basis and provide a record of changes on the Sun, measurements that are importantboth for short-term and long-term studies.

Coronal studies cover the full regime of visible coronal emission phenomena. Examples are the physicsof loops (heating mechanisms, electric fields, flow velocities, stability, evolution, reconnection,polarization), coronal holes (morphological characteristics, flows, temperature, sector boundaries),transients, streamers, and general morphology. Measurements of the emission of three coronal linesrepresenting different coronal temperature regimes are transmitted daily to national solar forecastingcenters. The low-polarization and low-scattered-light instrumental charaaeristics of the main coronagraphpermit studies of the polarization of prominence emission and deduction of veaor magnetic fields. Thesame techniques can be applied to the study of sunspots.

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The Hilltop Facility at Sac Peak has several small telescopes dedicated to synoptic programs as well assome new technology telescopes; all are mounted on a common spar. The instrumentation includes awhite-light-flare telescope and a 20-cm aperture, two-emission-line coronagraph, a Fabry-Perotetalon-based vector magnetograph, and two prototype reflecting coronagraphs. The set of Hilltop patrolinstruments automatically monitors flares, sunspots, coronal, and other solar phenomena throughout eachday.

The McMath Telescope complex at Kitt Peak contains three telescopes in one inclined enclosure (the1.6-m main and two .76-m auxiliaries) permitting three conjoined or independent research projects to berun at one time. The Vacuum Telescope on Kitt Peak and the small Razdow patrol instrument comprisethe second solar complex on Kitt Peak.

At the McMath Telescope, the available solar instrumentation includes a long-focal-length, high-dispersionspectrograph and the Fourier Transform Spectrometer (FTS). The FTS has a unique combination ofspectral resolving power (typically .3 - 1.0 x 106), total spectral range (0.25 - 18 um), simultaneousspectral coverage (up to a factor of four in wavelength), wavelength accuracy (vacuum wavenumbers tobetter than one part in 109 ifenough photons are available), and freedom from scattered light. In addition,a large and active program of laboratory spectroscopy is carried out at the FTS. Additional instrumentationcan be brought to any of the telescopes. The work at the McMath facility centers around its capability forhigh spectral resolution and for infrared work. Freedom from scattered light makes the McMath Telescopeparticularly valuable for solar and planetary research. Because of its large aperture and all-reflectingdesign, the McMath Telescope is ideal for infrared work in the wavelength region 1 - 15 um. Infraredobservations have been re-emphasized at the McMath facility during recent years, yielding exciting newresults on photospheric magnetic fields and the thermal structure of the solar atmosphere. The solar-stellarcommunity makes use of a dedicated spectrograph and a high signal-to-noise CCD spectrograph for thestudy of solar type phenomena that appear in stars like the Sun

The Vacuum Telescope on Kitt Peak, supported in part by NASA/GSFC and NOAA/SEL, is used for dailymagnetic observations of the solar surface and the acquisition of Helium 10830 A spectroheliograms. Ithas recently been upgraded by the addition of the Spectromagnetograph, which provides an improvementin the quality of the magnetic data and also allows for the accurate measurement of velocity fields.Oscillation observations are also carried out at the Kitt Peak Vacuum Telescope.

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Table 7

NSO Telescope/Instrument Combinations

Vacuum Tower Telescope (SP)Echelle SpectrographUniversal SpectrographHorizontal SpectrographUniversal Birefringent FilterFabry-Perot Interferometer Filter SystemAdvanced Stokes Polarimeter

Slit-Jaw Camera SystemsCorrelation Tracker

Branch Feed Optical SystemHorizontal and Vertical Optical Benches for visitor equipmentOptical Test Room

Evans Solar Facility (SP)40-cm Coronagraphs (2)30-cm Coelostat

40-cm TelescopeLittrow SpectrographUniversal SpectrographSpectroheliographCoronal Photometer

Dual Camera System

Hilltop Dome Facility (SP)Ha-Flare Telescope MonitorWhite-Light Telescope20-cm Full-Limb CoronagraphWhite-Light Flare-Patrol Telescope (Mk IT)Sunspot TelescopeFabry-Perot Etalon Veaor MagnetographMirror-Objective Coronagraph (5 cm)Mirror-Objective Coronagraph (15 cm)

McMath Telescope Complex (KP)160-cm Main Unobstructed Telescope76-cm East Auxiliary Telescope76-cm West Auxiliary TelescopeVertical SpectrographInfrared ImagerImage Stabilizers1-m Fourier Transform SpectrometerStellar Spectrograph System3 Semi-Permanent Observing Stations for visitor equipment

Vacuum Telescope (KP)SpectromagnetographHigh /-Helioseismograph

Razdow (KP)Ha patrol instrument

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V. NOAO OPERATIONS

A. Scientific Staff

NOAO is a service organization, charged with the responsibility of building and operating state-of-the-artfacilities for the community. In order to carry out this task, NOAO must necessarily also be a researchorganization of the first rank. The quality of service that is provided to the community of observers thatwe serve is directly linked to the quality of the NOAO scientific staff.

It is the scientific staff that must work with the community to identify major opportunities in astrophysicalresearch and on that basis define the future course of NOAO. They prepare proposals for major newtelescopes, oversee the design and construction of new instruments, and monitor the performance ofexisting facilities. The scientific staff provides the link between NOAO and the users of its observatoriesand in this way evaluates how well the programs at NOAO match the needs of the astronomicalcommunity. The staff is also an important repository of the technical information necessary in order todesign and build new telescopes.

During the next five years we plan to maintain the scientific staff at approximately its current size. Weexpea between two and four retirements during this time period and plan to fill those vacancies withpeople who can play key roles in the development of the new facilities now being planned by all threedivisions. During this same time period, we will also achieve the goal of having three post-doctoralpositions in each of the three divisions.

NOAO is developing stronger policies and procedures for post-tenure review, which already includesannual evaluations by the appropriate director. Salaries are not competitive with umversity astronomyprograms of comparable stature, and over the next several years this disparity will be eliminated whereperformance merits higher salaries. We have implemented an emeritus program to make it possible formembers of the scientific staff who retire to remain active in research. We will also review and clarifythe career track for those members of the scientific staff who devote most of their time to the constructionof innovative instrumentation.

B. Computer Support

Downtown Tucson Computer SupportThe computer facilities run by CCS in the Tucson office complex serve three general needs forNOAO-Tucson: data reduction and analysis for the scientific staff and visitors, general computing for allstaff members, and IRAF development and support Our distributed computing strategy for Tucsonimplements a combination of central, shared facilities, and a variety of desktop facilities includingworkstations and modem, smart terminals. Computing systems are linked with real or virtual ethemets,transmitted by wire in Tucson, optical fiber on KittPeak, and leased-line between Tucson and Kitt Peak.

In FY 1992 we will complete an extensive improvement program to our central computing facilities,replacing older high-maintenance systems with modem low maintenance ones, achieving concurrendy amajor upgrade ofcapabilities. Insubsequent years, we will continue ourprogram ofupgrades for increasedperformance with reduced maintenance and operating costs. In general, the lifetime of a computer orperipheral is four years.

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Thus, in FY 1993 we will replace the server for the Science Workstation Network, Gemini. In FY 1994and FY 1995, our "fast" machine, Ursa, and our VMS machine, Robur will be replaced, with the IRAFdevelopment machine, Tucana, the general timesharing machine, Orion, and the printer control machine,Solitaire, replaced in FY 1996 and FY 1997.

A discussion of archiving appears at the end of the section on computer support.

Table 8

NOAO Tucson Schedule of Major Capital Expenditures

Item FY 1992 FY 1993 FY 1994 FY 1995 FY 1996 FY 1997

Central facilities 100K 125K 125K 125K 125K 125K

Archiving as above OK 83K 180K 165K 260K 192K

100K 208K 305K 290K 385K 317K

Kitt Peak Computer SupportThe facilities on Kitt Peak use computers for control of instruments and telescopes, for data reduction(using IRAF), and for the general computing needs of the mountain staff. Over the next five years, wewill continue to replace the control computers, provide sophisticated IRAF systems for all observers, andgive each telescope a data acquisition computer for instrument control and quick look capabilitiesindependent of the main IRAF reduction computer. New or augmented facilities will be required toprovide a central database server that will allow computer access to an extensive collection of astronomicalcatalogues as well as lists of individual observer's program objects. This system will also be used toarchive CCD images as they are taken at each telescope. The TI link to downtown will become saturatedwhen image size increases (mosaics) and hardware will be required to improve the link to meet thedemand. In addition, funds are required to support the distributed data reduction facilities in Tucson.

Table 9

KPNO Schedule of Major Capital Expenditures

Item FY 1992 FY 1993 FY 1994 FY 1995 FY 1996 FY 1997

Telescope control 30K 30K 25K 20K

Instrument control 20K - 20K 20K 20K 20K 20K

IRAF data stations and upgradesto existing systems 35K 45K 50K 50K 40K 40K

Computer spares 25K 30K

Database server 10K 10K 20K

Ethernet-FDDI conversion 15K 15K 10K 10K

High speed communication upgrades 30K 30K 20K

Distributed computing 60K 60K 60K 60K 60K 60K

155K 180K 200K 170K 175K 190K

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Cerro Tololo Computer SupportComputer plans at Cerro Tololo are similar to those in Tucson and on Kitt Peak. A fully integrateddistributed computer network now exists between Cerro Tololo and La Serena, but this will need to beconsiderably enhanced in order to handle efficiendy the huge data rates that will be produced by the newgeneration of large format detectors and mosaics. At the most basic level, we will need to purchaseadditional individual scientific workstations and upgrade existing ones; some of our equipment isbecoming obsolescent and must be upgraded as technology advances. We shall continue to enhance thecapabilities and reliability of the Sun computers at the five major CTIO telescopes, as these will besupporting real time data acquisition when the new array controllers come into routine use with CCDs andIR deteaors starting in FY 1993. We will also need to increase the speed at which the network functionsso that it will not become clogged by the ever-increasing amount of traffic passing over it The latter willbe done by replacing our current Ethemets with Fiber Distributed Data Interconnection (FDDI) systems.

CTIO intends to begin archiving astronomical data in conjunction with KPNO, using well-definedstandards so that data will be fully interchangeable between sites and easily accessible to users. Routinestorage of data will probably begin during FY 1993 with all the data archived and made accessible to theastronomical community once standards have been established.

A dedicated microwave link has been established between La Serena and Cerro Tololo, with a TI (1.544Mb/sec) data channel providing high speed connection of the mountain and downtown computer networks.This system was funded as an experiment. It has neither backup nor spares. Because repairing equipmentof this type in Chile is difficult, it is necessary to begin the purchase of essential spares, and eventuallywe plan to install a full backup channel. A second channel will also double the data transmissioncapacity,which will become necessary as the traffic on the network increases.

NASA has funded a three year experiment to connea CTIO directly to the Internet via a 56 Kbauddedicated satellite uplink facility on Cerro Tololo. This experiment is designed to demonstrate the valueof having CTIO well-connected to the US networking system and to allow experiments in remoteobservation. This link has now been in operation for approximately 18 months and has already becomeheavily used. It has shown itself to be extremely valuable in the operation of NOAO and CTIO.Experiments in remote observing will begin during FY 1992.

NASA funding for this link will terminate during May 1993. During FY 1993, we plan to install adedicated link of at least 64 Kbaud between CTIO and KPNO, increasing the bandwidth as the need isdemonstrated and as funds are available. This link will allow greater integration of the two observatories,permitting joint data archives and remote observing as the bandwidth permits. As better communicationchannels become available, we will begin to install some equipment to allow routine remote observing asappropriate. We expea to begin this process in FY 1994 after the dedicated CTIO/KPNO link becomesoperational.

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Table 10

CTIO Schedule of Major Capital Expenditures

Item FY1992 FY1993 FY1994 FY1995 FY1996 FY1997

Distributed ComputingEquipment UpgradesCTIO-KPNO Satellite Link*

40K

30K

30K

30K

30K

25K

30K

75K

25K

65K

60K

30K

70K

60K

30K

70K

100K

Ethernet-FDDI Conversion 35K 35K

Microwave Spares/BackupRemote Observing FacilitiesArchiving - Capital**

Total 70K

45K

40K

210K

15K

60K

240K

40K

50K

240K

20K

10K

190K

20K

10K

230K

* Includes both operational costs and costs of upgrading capacity."* Manpower required will probably add 30K/yearcost beginning in FY 1994

NSO/SP Computer SupportThereare threecomputerfacilities at NSO/Sacramento Peak: MainLab (ML),Evans Solar Facility(ESF),and the Vacuum Tower Telescope (VTT). The ESF and VTT computer systems are mainly used fortelescope control, data collection, and limited analysis. They are not set up for general computing. TheML facility is used for data reduction, analysis, and general computing.

Table 11

NSO/SP Schedule of Major Capital Expenditures

Item FY1992 FY1993 FY1994

A/C (all sites) replacementNetwork GatewayDistributed Workstations

Compute ServerFDDI network

Server/Workstation upgradeOptical Disk System

Total

xpenditures

FY1995 FY1996 FY1997

45K

25K

100K

45K 25K 100K

20K

20K 24K

30K 60K

300K

60K

e 60K lOOK

75K

110K 404K 235K

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Specific aspects of the plan for NSO/SP are as follows:

1. Replace the old A/C systems with more efficient cooling systems at the ML, VTT and ESF.

2. Upgrade our Internet connection to include a dedicated network gateway and TI speed line fromSacramento Peak to Apache Point.

3. Install/upgrade workstations in scientific staff offices.

4. Install a "compute server" to handle the increase in data collection. This would be in the 100 MFLOPScpu(s) range with 10 Gigabytes of high-speed on-line disk space.

5. Install a 20 GB optical disk hierarchical storage system. The system will allow infrequent accessedfiles to be off-loaded from magnetic disk to optical storage, yet be accessible on demand. This willalso permit users to begin archiving data from outdated magnetic tapes to a more reliable long-termarchive storage system.

6. Upgrade the ethemet network to FDDI. This will be needed to handle the increase in data traffic. Theminimum link needed would be between the ML and the VTT.

7. Upgrade/replace old file servers and workstations.

With regard to Tucson/Kitt Peak computer plans, there are two basic areas which NSO/Tucson would liketo address: providing high quality workstations to our staff, and providing for the ongoing upgrading ofthese systems in the out years. Initially five workstations for the staff will be procured with additionalstations in the out years. The doubling time for computer performance is two to three years. A mountainworkstation will also be upgraded at the outset, and thereafter other systems will be upgraded at intervalsof roughly two years. Furthermore, the data acquisition system at the McMath will also be the subject ofa major modernization program.

1 Table 12

NSO/T and NSO/KP Schedule of Major Capital Expendit ures

Item FY1993 FY1994 FY1995 FY1996 FY1997

Distributed workstations 100K 20K 20K

Workstation upgrades 20K 20K 20K

McMath data acquisition 50K 50K

Total 120K 70K 70K 20K 20K

A Proposal to "Save the Bits" on Kitt Peak: A Bare-Bones Data Archive

The arguments for archiving ground-based astronomical data are compelling, and the call for the nationalobservatories, in particular, to archive their data is becoming more insistent. The recent Astronomy andAstrophysics Survey Committee report for the coming decade strongly recommends the establishment of

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ground-based data archives available to the community over computer networks. The reasons cited are1) archival material is of value to understand astronomical processes that occur on long time scales, 2) adefinitive understanding of astrophysics often results from extensive archival studies rather than from theinitial interpretations of data, and 3) ground-based array detectors provide a richdataset for serendipitousand exploratory programs.

The barriers to ground-based data archiving are also formidable. The varied funding sources of ground-based observatories, the wide variety and rapid evolutionof ground-based instrumentation, the historicallyproprietary nature of ground-based data, the high cost (relative to the acquisition of new data or theconstructionof new facilities) of establishing and maintaining data archives, and the difficulty of providingadequate documentation for the data to allow other astronomers to make intelligent use of it are all citedas reasons not to commit the resources necessary to develop ground-based data archives.

The reasons listed above for not archiving data are daunting, but they are not insurmountable. Thisproposal outlines a specific plan for archiving data on Kitt Peak both, solar and nighttime, and for makingthese data, as well as catalogs of the data, available to the community on a limited basis without thecommitment of substantial observatory resources in the process. If the approach proves successful, it canbe extended to other NOAO sites.

The scheme described here takes advantage of the new IRAF Control Environment (ICE), now in use onKitt Peak for CCD control and data acquisition, to collect the raw data and send it to a central archivecomputer on the mountain. The archive computer stores the rawdataon a low-cost mass storage medium,such as exabyte tape or digital audio tape, and sends the data header to a downtown "server" computerfor further processing. The downtown computer receives and stores the data headers and creates andmaintains two layers of data "catalogs" available over Internet. These catalogs are comprised of simpleone-line (i.e. 132 character ASCII strings) summaries of key information describing the data, includingsuch information as objea observed, telescope, instrument observer, date, and time. As simple ASCIIfiles, these data catalogs can be accessed directly by astronomers interested in locating data suitable fortheir research needs. These catalogs will also contain general comments (if available) from the observersdescribing the conditions of the observations (weather, instrument status, seeing, special problems, etc.).

Astronomers wishing to acquire archive data will first examine the top layer of the data catalog. This isa file (or files, for each telescope) containing the one-line descriptions of each "objea" image obtainedat a telescope. This file will not include descriptions of all the calibration frames, but just the actualobservational frames. If observations of interest are found, the astronomer can then access the next layerof the archive, which is comprised of files containing all one-line summaries of all data frames (includingcalibrations) taken at that telescope on the night in question. From these files, the astronomer can compilea list of actual images that might be needed to achieve specific research goals.

The next step is to examine the data headers appropriate for these images in order to confirm the need foreach image, as well as reduce, if possible, the list of images actually needed from the archive. Once a listof images is prepared, the astronomer can obtain permission from the Kitt Peak or NSO Directors toaccess the image archive. The Direaors will ensure that the proprietary rights of the observer are respectedand that the need for access to the image archive is scientifically justified. Access to the image archiveshould be controlled to limit the impact on the CCS staff. If appropriate, a tape of the required images canbe prepared for the astronomer requesting the data.

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The Data Volume

The volume of data generated per night on Kitt Peak is widely variable and difficult to estimate. The datavolume clearly depends on the number and size of CCDs in operation, weather, instrumentation, particularscience program, and style of the observers scheduled at each telescope. One of the auxiliary goals of thisproject should be to obtain a better estimate of the data volume generated at KPNO.

The data volume is most likely dominated by calibration frames (bias frames, flat-field frames, etc.). Ifwe have five CCDs in operation, each with 2048 x 2048 pixels, and we assume (about) 50 frames pernight per telescope, with 15 bits per pixel, the data volume is 2 Gbytes per night Even on a night of poorweather, observers generally obtain calibration frames that should be included in the archive. Anautomated pipeline will not "know" if the weather will improve later in the night! Also these calibrationframes may prove to be useful for engineering purposes.

The Archive Plan

The simple archive scheme described above can be broken down further into the necessary steps toestablish and operate the archive.

Actions Required of the ICE CCD Control ComputerThe ICE CCD control system being implemented on Kitt Peak provides a simple interface allowing accessto the data stream for archiving purposes. The ICE CCD control computer should be expected to do thefollowing:

1. Obtain the image from the CCD and attach a header to the image without making an effort to expandthe set of header parameters to be more complete. Use what is available now, with one exception: addone header parameter that is a unique identifier string for that image. The header information nowalready incorporated by, and into, ICE (telescope, instrument, detector, observer, comment RA, dec,date, times, etc.) is a good basic start Additional parameters may be added as appropriate.

2. Ship the image+header over the mountain Ethernet to an archive computer located, most probably, inthe NOAOTucson Headquarters building.Every image obtained with ICE (except those obtained withthe "test" task) should be saved. Once this is accomplished, it may be possible to save reduced data,but reductions are too spotty at this time to plan to use reduced data as a central archive.

3. ICE should offer the observer an opportunity to enter general comments ("tracking is poor," or"windy," or "good seeing!," etc.) whenever the CCD acquisition window is invoked at the beginningof the night and when the observer logs out at the end of the night The observer should also be ableto invoke the "comment" task throughout the night. The disposition of comments will be discussedlater, but the comments are not intended to be incorporated into the image header. Observers mighteven add comments after the image has been sent off to the "archive" computer, when incorporatingthem into the appropriate image header would be awkward, at best.

Actions Required of the "Archive" ComputerThe next parcel of responsibility is the purview of the "archive" computer in the NOAO TucsonHeadquarters building. On the adviceof Steve Grandi, the "archive" computer should be a Sun-ELC witha monochrome display, 24 MB of memory, 2 exabyte drives (or DAT, if appropriate), and a 1 GB harddisk. The two drives are for 1) redundancy if one should fail, and 2) overflow if one should fill up duringa night. The estimated cost of this hardware is $10-12K.

70

At the moment the cost effective choice for the mass storage medium is exabyte tape (with 5 GB pertape), but review of this situation should continue. Digital audio tape (DAT), at 3.5 GB per tape, may bea more appropriate and reasonably costeffective choice. The advantages of DAT are 1) less wearand tearon the medium by the drive, and 2) it is a "coming" technology that offers a longerlifetime. Several DATdrives have already been obtained by NOAO, and experience with this technology is being acquired.

Summary of primary archive computer actions:

1. Receive images+headers from the various ICE CCD controllers around the mountain and write theimages+headers to the buffer disk. Images will be coming in from all the various CCD ICE systemson the mountain at random times.

2. Add (or set) header parameters indicating 1) that the image has been archived, and 2) to what tapenumber the data are written.

3. Write the image+header to the tape, in the order received at the "archive" computer.

4. Mail the header (only) downtown.

5. Log the unique image ID string in the header and the tape number in a file in the archive computer.

6. Delete the image+header file(s).

Actions Required of the Downtown ServerOne downtown server should be designated as the "recipient" of the data headers sent from the mountain"archive" computer. The downtown computer should aa in the following manner:

1. Upon receipt of a header, obtain from the header a one-line summary of the most importantinformation. The line should be restricted to 132 characters, including blank spaces for readability.This line should, at a minimum, include the unique ID string, archive tape number, telescope,instrument (including detector ID), name of principle investigator/observer, objea name (i.e., 20characters), RA and dec, and image type (bias, comp, flat, object etc.). If the epoch is not 1950 (orwhatever is decided), the coordinates should be processed to the standard epoch, so that epoch doesnot have to be included in the 132 characters.

2. Compress the header and store it permanenUy on disk. This may or may not be practical dependingon the number of headers generated. The file name might be the unique ID string, for example.

3. For each night and telescope, the one-line header summaries of all the images obtained should beplaced in a file. We will probably need to establish a tree of directories for telescopes and, perhaps,months so that the nightiy files can be found easily.

4. Establish a top-level file of one-line header summaries which contains only the one-line summariesof actual objects (i.e., no biases, flats, comps, darks, etc.). To keep the size manageable, we will alsoneed to break this into several files according to telescope and/or month. It is this top-level file thatwill provide front line staff and visitor access to the "archive." Users who want to know what datahas been obtained by whom on a particular source can use standard editors or "grep" to search the top

71

level file for their objects or coordinates. Individuals can also write their own simple Fortran, C, orcomparable programs to search the files.

5. In addition to the one-line summaries, the nighdy files should also contain any comments the observeradds from the "comment" task in ICE. These should be e-mailed down to the server handling thearchive, stripped of the e-mail header, included in the nighdy file, and merged into the time sequenceof the observations. Comments in the top-level objea file may also be included.

6. The top-level and nighdy files should be available over Internet.

Required "People" Resources to Maintain the ArchiveObservatory staff will be needed not only to set up the data archive procedures, but also to keep itoperating smoothly. The operations effort will include several steps:

1. Downtown staff will need to keep the mountain supplied with exabyte tapes for the primaryimage+header archive. These tapes should be labeled externally before being sent to the mountain.

2. Mountain staff will need to insert one or two new tapes into the "archive" computer tape drives eachday, as well as enter the tape label IDs into the computer so the tape number can be added to eachheader.

3. Tapes containing archived data should be sent downtown by the mountain staff.

4. Downtown staff will need to receive the archive tapes from the mountain, log them in, and store themin a safe place.

5. Downtown staff will need to respond to requests for information on how to retrieve data from thevarious levels of the archive. Access to the top two levels of header summaries (the running file(s)of objects observed, and the nighdy telescope files with a complete list of images obtained) shouldbe straightforward, with perhaps a page of descriptive documentation on how to find the files. Accessto the third level of the header archive may require more extensive user assistance or documentation,but should also be available over Internet Access to the deepest layer of the image+header tapes willrequire involvement by NOAO staff and should be allowed only upon application to the Director ofKitt Peak.

6. A manager will have to be selected to oversee the whole operation and ensure that the data areflowing smoothly.

Policy on Access to the ArchiveAURA's policy of eighteen months of proprietary time for the principle investigator (PI) should befollowed. People other than those associated with the proposal or designated by the PI should not haveaccess to the actual data until eighteen months after it is taken. Access to the image archive should requirepermission from the Kitt Peak Director to ensure the proprietary rights of the observer, guarantee that theneed for access is scientifically justified, and limit impaa on the support staff.

Advantages of the "Save the Bits" PlanThe proposed data archiving plan is not the ideal, but it does offer the following advantages to NOAO/Kitt Peak:

72

1. Theproposal canbe implemented with minimal effort, begin saving bits, andevenallow some limitedaccess to the data.

2. The data collected can be used to understand the volume and types of data generated at NOAO so thata more "professional" archive can be intelligendy planned.

3. The scheme is loose enough and the investment small enough that we can change and improve it aswe learn. For example, more complete header information can be added by ICE. Reduced data canbe added in a parallel pipeline. A proper database system, perhaps one of those developed at one ofour sister observatories, can be incorporated.

C. Facilities Maintenance

The inadequate operating budgets of the past decade have caused a severe deterioration of facilities at allfour NOAO sites. Present funding is inadequate to address these deficiencies. If there is any hope ofbringing the facilities back to standard levels, a substantial increase in maintenance funds must be madeavailable. An increment in funding of - $500K/year is essential.

The maintenance requirements identified to date for all sites are summarized in Table 13. Comments onspecific issues at each of the sites follow:

73

Table 13

Maintenance Requirements

Maintenance and Safety SummaryCTIO $ 845K

KPNO 1.091K

NSO/Kitt Peak 262KTucson 637K

NSO/Sacramento Peak 1.539KTotal $4,374K

Maintenance and Safety, CTIOBuilding for observer support and machine shop $125KReplace PCB transformers 50KReplace metal water pipes on Tololo 40KInstall a 200 KVA back-up generator at La Serena 75KReplace metal warehouse and shop buildings on Tololo 200KReplace road grader 195KGuard rails for Tololo road 160K

Maintenance and Safety, KPNOGeneral building repairs/improvements $350KMirror seal two water catchment basins 60K

Crane, elevator, fire alarm inspection/repair 140KRoof repairs 90KRoad repairs 60KSeptic system maintenance 45KRepair of power poles and lines 65KCompletion of central fire alarm system 40KReplacement of underground telephone lines 65KUpgrade of telephone system 51KDevelopment of inventoried storage facility 125K

Maintenance and Safety, NSO/Kitt PeakSurvey and overhaul of McMath electrical system $100KModify #3 mirror mount to allow safe handling 7KGuard to prevent fall from Vacuum Telescope elevator 10KGeneral upgrade of McMath Telescope 145K

74

Maintenance and Safety, NOAO TucsonComplete remaining roof repairs $70KImprovements to interior of headquarters building 60KCorrea building power distribution problems 100KUpgrade headquarters building telephone system 60KCorrea headquarters building (HVAQ problems 80KUpgrade of fire alarm system 82KUpdate of facilities electrical/mechanical drawings 50KInstall building energy management systems 135K

Maintenance and Safety, NSO/Sacramento PeakResurface roads, driveways, and parking lots $300KFire detection system 40KReplace a segment of water mains 95KReplace a segment of gas mains 35KPaint and reroof buildings 295KMotor generator replacement 35KModem vehicles/equipment 359KRepair sidewalks and rock walls 20KUpgrade underground storage tanks 15KPlating room upgrade 35KAdditional craftspersons 31OK

Facilities Maintenance, Cerro TololoThe CTIO infrastructure, including electrical lines, the water distribution system, and the roads, is in needof renovation. A substantial fraction of pipes and wires have become corroded over the years and mustbe replaced. In FY 1990, a five-year program was begun to accomplish this work. Considerable progresshas already been made on replacing corroded pipes on Tololo, but a substantial amount of work remains.The Tololo roads need constant maintenance, both paved and dirt, and the road to Pachon will need tobe improved before telescope construction can begin at that site. The Caterpillar 12-E road grader, whichhas been in operation since 1964, has become increasingly difficult to maintain due to the shortage ofavailable spare parts in either Chile or the US. It should be replaced before development of Cerro Pachonproceeds. A program to install guard rails at certain critical areas of the Tololo road will be expanded overthe next few years to include a few dangerous sections of the Pachon road.

At the present time, emergency electrical power exists for Tololo from a back-up diesel generator, but notfor La Serena. Thus, the power outages that are common in Chile take down all of the computers andelectrical equipment, sometime for as long as five hours. A 200 KVA back-up generator is needed for theLa Serena compound as soon as funds can be made available.

Due to level funding, renovation of the CTIO vehicle fleet has been postponed for several years. As aconsequence, two-thirds of the observatory vehicles average more than six years of use, and the rest areover fifteen years old.

75

Facilities Construction, Cerro TololoDuring FY 1990, CTIO began an intensive effort to improve the thermal environments of the 4-m and1.5-m telescopes. One of the main goals of this projea is to remove as many sources of heat from the 4-mand 1.5-m buildings as possible. As an important first step, the electronics laboratory and offices weremoved from the 4-m dome to the former visitor center, just below the level of the summit, and the librarywas moved to the Round Office Building. During FY 1991, the Observer Support personnel were movedout of their offices and into the area originally occupied by the hbrary, thereby providing room for a new4-m telescope console room on the first floor of the 4-m building. This new console room is scheduledto be become operational by the end of FY 1992. Plans also call for the 1.5-m telescope console roomto be moved to the second floor of the 1.5-m building, but this will probably not take place until FY 1993.On roughly the same time scale, the Tolnet computer room on the Pump floor of the 4-m building willbe eliminated. A final important step will be the removal of the Observer Support offices from the 4-mand the machine shop from the 1.5-m, but this move will require the construction of a new building. Thenew building, which should also be large enough to house an observer's lounge and the library, is to belocated next to the electronics lab (just below the summit) and will be constructed using low-costprefabricated steel and polyfoam panels. This building is CTIO's highest priority construction projea overthe next five years.

Since 1963, the frequency converter, warehouse, garage, and several shops on Tololo have been housedin "temporary" buildings of structural steel covered only with corrugated zinc sheeting. The buildings areunsuitable for the mountain weather conditions and have become less safe with age. Their replacementwith prefabricated service buildings is proposed for FY 1993 and 1994.

Facilities Maintenance, KPNOThe aging of the facilities on Kitt Peak, along with the occasional harshness of the environment continueto present severe maintenance problems. Until substantial additional funds for facilities maintenance aremade available, maintenance will be limited to the most urgent problems. Renovation of the 4-m telescoperemains a high priority. It is anticipated that work on this multi-year project will begin in FY 1992. Majoritems include a new telescope control system, painting the upper area of the dome, overhaul of the dometrucks, upgrade of the aluminizing facility, correction of the building ingress/egress fire safety problem,and upgrading of the guider/rotator. Other major facilities work includes mirror sealing of two watercatchment basins; a very large number of general building repairs; upgrade of maintenance shopequipment and update of the mountain telephone system.

Work remaining to be completed at the McMath telescope includes a general overhaul of thecontrols/electrical system and improvements to the mirror handling equipment In addition, the Vacuumtelescope elevator guard remains as a long outstanding safety item.

Additional smaller projects include the completion of the underground fuel storage tank project;replacement of various underground water, sewer and telephone lines; completion of the mountain-widefire alarm system; and modifications to the administration and kitchen buildings.

Facilities Construction, KPNOThree non-NSF funded construction projects (WIYN telescope, Visitor Center modification, and the 16-inch visitors' telescope) remain as planned projects for this period. In addition, a new tenant, theSoutheastern Association for Research in Astronomy (SARA), will construa a new building and domefor their 0.9-m telescope on Kitt Peak sometime in FY 1992. The involvement of KPNO in this projectis expected to be limited to on-site inspections and occasional construction support.

76

Facilities Maintenance, NOAO TucsonThe major facilities maintenance requirements at the NOAO Tucson headquarters building continue to bethe inefficient and unpredictable heating/cooling system, an unbalanced electrical system, andthe need toreplace aging physical plant equipment As a result, the major emphasis of ourmaintenance plan will beto correct these deficiencies.

Other projects include the following: completion of our long-term re-roofing project therepair/replacement ofseveral forklifts; updating ofall ourelectricalAnechanical drawings; limited purchasesofenergy management equipment; thepurchase ofnewly required freon containment equipment; continuedreplacement of our vehicle shuttle fleet completion of the exterior painting of the headquarters building;updating of the headquarters telephone system; and the replacement of our large cargo truck.

Facilities Construction, NOAO TucsonThe increased staffing levels for the Gemini andGONG projects haveplaced a heavydemand on availablespace within the NOAO headquarters buildings. The newly-hired staffhave been accommodated throughcompletion of the portable office building for the Gemini program, conversion of several basementlaboratories to office space, construction of five new offices as an addition to the Central AdministrativeServices building, and conversion of the duplex visitor apartments to office space. In October of 1992,the AURA Corporate Building will be remodeled to become the home of the GONG data center.

While most space needs are being supported, this situation is only a short-term solution. Discussion withthe University of Arizona regarding the relocation of NOAO continues. As an alternative, the upwardexpansion of the headquarters building east wing has been carefully reviewed. A recommendationregarding the two options will be made to AURA and the NSF in FY 1992.

Facilities Maintenance, NSO/Kitt PeakThe McMath telescope was constructed more than thirty years ago and several improvement projects havebeen defined for this facility. These include, but are not limited to, the constructionof new work platformsand modifications to the building layout in order to improve workspace, including access for maintenance.

Facilities Maintenance, NSO/Sacramento PeakThe central station of a modem fire alarm system was installed during FY 91 and three buildings havebeen connected. Additional buildings will be added to the system during the next five years. The roof ofthe Vacuum Tower Telescope building was replaced, and the roofing of the two IDL buildings was alsocompleted. Four new boilers have been purchased and will be installed during FY 92. NSO also replacedthe commuter van and a facilities maintenance pickup truck.

With the exception of the twenty-one relocatable housing units that were erected in the mid-1960s and theVacuum Tower Telescope that was completed in 1969,most of the buildings and infrastructure of NSO/SPwere constructed in the early to mid-1950s. In the years preceding the transfer of SPO to the NSF, theUSAF ignored facilities maintenance and the replacement of vehicles. The transfer to the NSF wasaccompanied by $250,000 of US Air Force funds that were used to remedy certain safety andenvironmental problems, but only a small amount was available for building maintenance. To furthercompound the problem, the budget for the past several years has not permitted NSO/SP to have aneffective preventivemaintenance program, and the result is a plethora of deferred maintenance items. Thevast majority of maintenance performed has been reactive in style, rather than preventive, with much ofthe work characterized by repair rather than replacement.

77

A five-year plan, which includes the resources necessary to bring the existing facilities up to a reasonablestandard, to establish a preventive maintenance program, and to replace obsolete equipment and vehicles,has been prepared. The average increase in annual expenditures under this plan is $380K/year.

Facilities Construction, NSO/Sacramento PeakAn addition to the Main Lab building continues to be the NSO/SP highest priority construaion item.Office and data reduction space are inadequate to meet the needs of staff and visitors. Lack of storagespace is also a critical problem and has forced us to store many items more than 20 miles away in anon-ideal environment. Transporting these items back and forth is extremely inefficient. A storage buildingwith an attached covered parking area for maintenance vehicles has been on the NSO/SP master plan formany years. An addition to the Instrument Development Laboratory building would provide a ground levelwelding shop. The present space used for this purpose requires the lifting of heavy objects several feetand is a safety hazard. The lack of a Visitor Center and adequate parking space for visitors is anincreasingly acute problem. The maintenance funds listed in Table 13 do not include support for this newconstruction.

78

VI. BUDGET

The budget and staffing tables that follow show staffing and funding for observatory operations and forGONG. In preparing these tables, we have assumed 10 percent real growth in FY 1993 and FY 1994 and5 percent (inflation only) in the remaining years of the plan. These numbers conform approximately tothe guidelines provided to the NSF by OMB. They do not conform to the President's budget for FY 1993,which requires a reduction in the NOAO program. We have not decided where to make the cuts, and socannot prepare an accurate budget for FY 1993. In any case, forcing the budget to conform to thePresident's request is to acquiesce in the continuing deterioration of NOAO. We have already cut by thebudget in real terms by 25 percent since 1984. It is time to re-invest in the national observatories.

The growth in the budget would be used to undertake the following initiatives:

• Initiate a program of deteaor acquisition and processing that over a period of five years would equipall of the telescopes and instruments at all of the sites with large format optical and IR deteaors.

• Initiate programs that would lead to improvements of 30-50 percent in the median image quality atthe KPNO and CTIO 4-m telescopes. This improvement in image quality is equivalent to a 30-50percent increase in aperture.

• Provide scientific input into the development of adaptive optics and limited suppport for collaborativework in interferometry.

• Establish a program that would provide for replacement of the computers within the observatories ona 5-7 year time scale.

• Initiate a prototype archiving program.

• Initiate a program to upgrade engineering equipment to achieve the efficiences offered by CADsystems and by computer-controlled machine tools.

• Initiate a program of maintenance that over a period of five yers would correct the outstandingproblems associated with deferred maintenance.

Funds are also provided in this budget to cover inflation in costs denominated in pesos at a rate of 15percent/year during the first two years of the five year plan

Staffing costs at the present time constitute approximately 70 percent of the NOAO budget. The requestsin this budget reduce the fraction of the budget devoted to staff costs, as is appropriate given the need forfunds for equipment and for outside contracts for facilities maintenance. However, additional staff are needin key areas.

At KPNO, we require additional scientific staff to maintain an adequate level of operations at Kitt Peak,given the large amount of staff time being devoted to Gemini. In addition, we need resources to implementqueue, service, and synoptic observing for the community at the WIYN. The budget contains three supportscientists and one observing technician. An IRAF support person is required to assist with data reduction

79

at the telescopes and with maintenance of IRAF systems on the mountain. An additional mechanicaldesigner is needed to support programs to upgrade telescope performance.

At NSO/SP the budget contains funds to support adaptive optics development (one engineer, onetechnician), and additional scientist (there are only five now at SP), another observer, and a craftspersonto assist with facilities maintenance. Of all the NOAO facilities, SP is the oldest and in the most desperateneed of repair.

At NSO/Tucson, the priorities are to enhance the solar-stellar program by adding a scientist and a postdoc, to use the McMath and the FTS full time rather than half time by adding two observers, and todouble the personnel devoted to instrumentation projects by adding an engineer and a technician.

At CTIO, the priorities in staffing are for a programmer to supportsystem software for the Sun computerson the mountain; a circuit designer who is skilled in the use of CAD-CAE. The budget also calls for theaddition of a scientist with expertise in optics. Since the site tests show that the median seeing on CerroTololo is about half what is actually achieved in the focal planes of the large telescopes, improving imagequality is the single most important step that can be taken to maximize the science output at CTIO.

The budget provides funds to initiate a program for training engineers in Tucson. Four junior engineerswould be hired into two-year appointments, and the assignments would be varied to ensure each engineeris exposed to a broad spectrum of telescope and instrument problems. We expect that this hands onexperience would supplement the formal training received at a university and that at the end of two yearsthese individuals would be strong candidates for permanent appointment either within NOAO or at anotherastronomy organization. It is particularly important that we take this step since in many areas we haveonly one engineer with the necessary expertise for our program, and many of these engineers will retirein the next five to ten years.

In addition, the budget provides for one master optician for Tucson. More than ten years ago, NOAOdecided to limit optics production capability and rely on commercial vendors for the standard 1/4 waveoptics that were then required for telescopes that performed at resolutions of 1 arcsec. Today, instrumentsare being designed for diffraction-limited telesocpes. It is our experience that commerical vendors cannotbe relied upon as the source of 1/10 to l/20th wave optics at a reasonable cost. The master optician woulldbe the cornerstone for rebuilding the NOAO optics fabrication capability.

The budget provides funds for a new position that would provide for scientific oversight of computeractivities, including IRAF. Scientific leadership, particularly in relation to IRAF, has been lacking withinthe observatory. With Steve Ridgway's resignation as head of CCS in order to work on interferometry andadaptive optics, the situation has become critical.

Both KPNO and NSO would like to enhance their archiving programs. Three new positions are allocatedto these programs.

80

Observatory OperationsScientific Staff & SupportOperations & MaintenanceInstrumentation

Management FeeSubtotal Observatory Operatjons

USAF & NASASupport of NSOTotal Observatory Operations

3.5-m Mirror Project

Global Oscillations Network GroupSubtotal

Initiatives

TABtE I

NATIONAt OPTICAt ASTRONOMY OBSERVATORIES

FY 1993 - FY 1997 tONG RANGE PLAN

BUDGET SUMMARY

(amounts in thousands)

FY 1992(1) FY 1993 FY 1994 FY 1995 FY 1996 FY 1997

5,034

16,909

3,390

475

25.808

5,733

20,200

3,947

499

30,379

6,257

22,396

4.411

524

33,588

6.572

23,616

4,555

550

35,293

6,900

24,796

4,752

578

37,026

7,243

26,037

4,915

607

38,802

(631)25,177

(663)29,716

(696)32,892

(731)34,562

(768)36,258

(806)37,996

844 910 645 677 711 747

2,317 2,550 2,550 2,100 1,470 1,330

28,338 33.175 36,087 37,339 38,439 40,073

Large Earth-based Solar Telescope (LEST) (2)DesignConstruction

1,600 504 238

1,000

$38,577

5,775

$44,214

4,725

Total Budget - NSF Funds $28,338 $34,775 $36,591 $44,798

(1) FY-1992 Program Plan Revision I (tentative) includes$27,954k new funds, and $384k carriedforward from FY-1991.(2) Funding costs to be shared with UCAR and HAO

Cerro Tololo Inler-Amencan Observatory

Scientific Staff & Support

Operations & MaintenanceInstrumentation

National Solar Observatory

Scientific Staff & Support

Operations & MaintenanceInstrumentation

Kitt Peak National Observatory

Scientific Staff & Support

Operations & MaintenanceInstrumentation

Central Offices

Director's Office

Scientific Staff & Support

Operations & MaintenanceInstrumentation

Central Computer ServicesScientific Staff & Support

Operations & MaintenanceInstrumentation

Central Administrative Services

Central Facilities Operations

Central Engineering & Technical Services

Publications & Information Resources

Total Central Offices

Management Fee

Subtotal Observatory Operations

USAF & NASA Support of NSO

Total Observatory Operations

3 5-m Mirror Project

Global Oscillations Network Group

Initiatives

Large Earth based Solar Telescope (LEST)Design

Construction

Total Budget - NSF Funds

TABLE II

NATIONAL OPTICAL ASTRONOMY OBSERVATORIES

FY 1993 - FY 1997 LONG RANGE PLAN

BUDGET SUMMARY

(amounts inthousands)

FY 1992 FY 1993 FY 1994 FY 1995 FY 1996 FY 1997

Personnel Other Personnel Other Personnel Other Personnel Other Personnel Other Personnel Other

Costs Costs Costs Costs Costs Costs Costs Costs Costs Costs Costs Costs

1,368 107 1,544 133 1,622 153 1,703 161 1,788 169 1,877 177

2.211 2,077 2,762 2,819 2,900 3,241 3.045 3,403 3.197 3.573 3,r" 3,752

487 251 602 373 632 425 664 420 697 415 7i2 415

4,074

6,500

2,435 4,908

8,232

3,325 5,154

8,973

3,819 5,412

9,396

3,984 5,682

9,839

4,15/ 5,966

10,310

4,344

1,120 105 1,256 121 1,439 139 1,511 146 1,587 153 1,666 161

1,553 695 1.801 999 2,081 1,149 2,185 1.206 2,294 1,266 2,409 1.329

572 70

870

601 170

1,290

631

4,151

204

1,492

663

4,359

226

1,578

696

4,577

248

1,667

731

4,806

274

3,245 3,857 1,764

4,115 4,947 5,643 5,937 6,244 6.570

1,875 250 2,089 288 2,253 331 2.366 348 2,484 365 2,608 383

3,571 1,426 3,850 1,840 4,042 2,116 4,244 2,222 4,456 2,333 4,679 2,450

1,356 314 1,424 374 1,495 514 1,570 507 1,649 527 1,731 573

6,802 1,990 7,362 2,501 7,790 2,961 8,180 3,077 8,589 3,225 9,016 3,406

11,814

120 11 126 13 132 15 139 16 146 17 153 18

509 38

68

117

534 44

78

135

561 50

82

147

589 53

86

155

618 56 649 59

629 660 693 728 764 73 802 77

78 2 162 2 170 3 179 3 188 3 197 3

579 259 698 298 833 343 975 360 1,024 378 1.075 397

112 150 118 208 123 305 129 290 135 385 142 317

769 411 977 508 1,126 651 1,283 653 1,347 766 1,414 717

1,082 383 1,136 440 1,193 507 1,253 532 1,316 559 1,382 587

576 956 605 1,149 635 1,322 667 1,388 700 1,457 735 1,530

564 304 742 350 879 402 923 422 969 443 1,017 465

113 13 119 15 125 17 131 18 138 19 145 20

3,733

5,917

2,184

475

7,954

4,240

6,837

2,597

499

10,212

4,851

7,697

3,046

524

11,842

4,985

8,153

3,168

550

12,357

5,234

8,551

3,317

578

12,944

5,495

8,891

3,396

607

17,854 20,167 21,746 22,936 24,082 25,285 13,517

25,808 30.378 33,588 35,293 37,026 38,802

(631) (663) (696) (731) (768) (806)

25,177 29,716 32,892 34.562 36,258 37.996

610 234 641 269 336 309 353 324 371 340 390 357

1,270

28,338

1,047 1,451

33,175

1,099 1,523

36,087

'1,027 1,349

37,339

751 1,016

38,439

454 967

40,073

363

$36.591

238

1,000

TABLE III

NATIONAL OPTICAL ASTRONOMY OBSERVATORIES

FY 1993 - FY 1997 LONG RANGE PLAN

STAFFING PLAN

(in Full Time Equivalents)

FY 1992 FY 1993 FY 1994 FY 1995 FY 1996 FY 1997

Scientific Staff & Support 62.55 67.55 70.55 70.55 70.55 70.55

Operations & Maintenance 318.58 330 58 337.58 337.58 337.58 337.58

Instrumentation 51.95 52.95 53.95 53.95 53.95 53.95

3.5-m Mirror Project 12.00 12.00 12.00 12.00 12 00 12 00

Global Oscillations Network Group 29.75 32.75 32.75 27.50 20.50 18.50

Total Staff 474.83 495.83 506.83 501.58 494.58 492 58

Scientists 64.00 69.00 72.00 72.00 72.00 72.00

Engineers & Scientific Programmers 83.25 90.25 96.25 94.25 92.25 9225

Administrators & Supervisors 32.50 32.50 32.50 32.50 32.50 3250

Clerical Workers 73.98 73 98 73.98 73.98 7398 73.98

Technicians 125.80 133.80 135.80 132.55 127.55 125.55

Maintenance & Service Workers 95.30 96.30 96.30 96.30 96.30 96 30

Total Staff 474.83 495 83 506 83 501.58 494.58 492 58