1

2

SOFIAStratospheric Observatory

For Infrared Astronomy

E. E. Becklin

SOFIA Chief Scientist

October, 2007

3

Outline

• Overview of SOFIA

• Progress to Date

• Science

• Schedule

4

OVERVIEW

5

Overview of SOFIA

• SOFIA is 2.5 m telescope in a modified B747SP aircraft– Optical-mm performance– The obscured IR (30-300 m) is most important

• Joint Program between the US (80%) and Germany (20%)

• First Science 2009 (NASA, DLR, USRA, DSI)

• Designed for 20 year lifetime

6

Overview of SOFIA (continued)

• Operating altitude– 39,000 to 45,000 feet (12 to 14 km)– Above > 99% of obscuring water vapor

• World Wide Deployments

• Ramp up to ~1000 science hours per year

• Build on KAO Heritage with improvements (Facility Inst., Science Support)

• Science flights to originate from NASA Dryden Flight Research Center (DFRC)

• Science Center is located at NASA Ames Research Center

SOFIA — The Observatory

open cavity (door not shown)

TELESCOPE

pressure bulkhead

scientific instrument (1 of 9)

scientist stations, telescope and instrument control, etc.

Educators work station

8

Why SOFIA?

• Infrared transmission in the Stratosphere very good: >80% from 1 to 1000 microns

• Instrumentation: wide complement, rapidly interchangeable, state-of-the art

• Mobility: anywhere, anytime

• Long lifetime

9

PROGRESS TO DATE

10

Main Deck, Looking Aft at Instrument Interface

Telescope Installed

Major Physical Installations Completed

11

Spherical Bearing

“First Oil“

The Bearing Sphere on the Nasmyth Tube

Rotation Isolation Subsystem

12

Primary Mirror (uncoated)

13

Telescope in Action

QuickTime™ and aMotion JPEG OpenDML decompressor

are needed to see this picture.

14

SOFIA rms Tracking of <0.8 arcsec

Tracker in centroid inertial tracking mode

500

510

520

530

540

550

550 560 570 580 590 600

Series1

15

SOFIA Makes Its First Flight!

16

SOFIA Arrival at NASA DFRC, May 31, 2007

17

As an airborne mission, SOFIA supports a unique, expandable instrument suite

• SOFIA covers the full IR range with imagers and low to high resolution spectrographs

• 4 instruments at Initial Operations; 9 instruments at Full Operations.

• SOFIA will take fully advantage of improvements in instrument technology. There will be one new instrument or major upgrade each year.

SOFIA’s Instrument Complement

18

Working/complete HIPO instrument in Waco on SOFIAduring Aug 2004

Working/complete FLITECAM

instrument atLick in 2004/5

Working FORCAST instrument at Palomar in 2005

Successful lab demonstration of

GREAT in July 2005

Four First Light Instruments

19

SCIENCE

20

Science Capabilities

• Because of large aperture and better detectors, sensitivity for imaging and spectroscopy similar to the space observatory ISO

• 8x8 arcmin Field of View allows use of very large detector arrays

• Image size is diffraction-limited beyond 25 µm, making it 3 times sharper than the space observatory Spitzer at these wavelengths

21

Astrochemistry

• Most ground state molecular lines in IR or submillimeter

• Need high spectral resolution throughout which SOFIA has.

• As sensitive as CSO, but much larger wavelength range is accessible

• Light molecules: Molecular hydrogen, HD, water, other hydrides in IR and submillimeter

• The fullerene, C60, has 4 IR lines in SOFIA’s bands

CSO FTS Spectrum of ORION OMC1

Serabyn and Weisstein 1995

SOFIA is an outstanding observatory to studychemistry in space

22

Occultation astronomy with SOFIA

Pluto occultation lightcurve observed on the KAO (1988) probes the atmosphere

•SOFIA can fly anywhere on the Earth, allowing it to position itself under the shadow of an occulting object.

•Occultation studies with SOFIA will probe the sizes, atmospheres, and possible satellites of newly discovered planet-like objects in the outer Solar system.

•The unique mobility of SOFIA opens up some hundred events per year for study compared to a handful for fixed observatories.

SOFIA will determine the properties of Dwarf Planets in and beyond the Kuiper Belt

23

The ground-based infrared spectrum of Mars is dominated by broad lines in the Earth atmosphere. A weak feature on the wing of the strong terrestrial methane line may be the Doppler-shifted methane line in the Mars atmosphere.

If true, the methane abundance is high and may reflect biogenic activity.

EXES working at 7.6 microns in the Stratosphere will be able to see directly the Doppler-shifted methane lines on Mars

How much methane is on Mars?

Does it show biogenic activity? What are the spatial and seasonal variability?

SOFIA will determine the Methane on Mars

Planetary Atmospheres

24

Today over 200 extrasolar planets are known, and over 15 transit their primary star SOFIA will fly above the scintillating component of the atmosphere and will provide the most sensitive freely pointing observatory for extrasolar planetary transits after HST and before JWST.

SOFIA’s HIPO and FLITECAM instruments can observe with high signal-to-noise the small variations in stellar flux due to a planet transit and

– Provide good estimates for the mass, size and density of the planet – May reveal the presence of, satellites, and/or planetary rings

Artist concept of planetary transit and the lightcurve of HD 209458b measured by HST revealing the transit signature

SOFIA will determine the properties of new extrasolar planets by use of transits with HIPO and FLITECAM working together

Extrasolar Planet Transits

25

Astronomers at ESO and Keck have detected fast moving stars revealing a 4 x 106 solar mass black hole at the Galactic Center

One of the major discoveries of the KAO was a ring of dust and gas orbiting the very center of the Galaxy at r=1pc

Young newly formed stars have also been found orbiting the black hole within 1000au

• Did these young massive stars form in the ring of dust and gas?

• If so, how do they get so close to the black hole?

• Are there other ways that the massive stars could form?

• SOFIA with its high angular and spectral resolution is well placed to help answer these questions over the next 20 years

SOFIA will help determine howstars form in the presence of a Massive Black Hole

Star Formation in the Center of the Galaxy in the Presenceof a Massive Black Hole

26

Antennae GalaxiesIRAC @ 8 microns (red; 160s, 4’ x 4’)FORCAST @ 24 microns

NASA/JPL-Caltech/Z. Wang

Henize 206- LMC high mass star formationMIPS @ 24 microns (80s, 20’ x 20’)HAWC @ 53 / 89 microns (mosaic)

NASA/JPL-Caltech/V. Gorjian

Resolving Star Formation: Spitzer & SOFIA

27

Atmospheric transmission around the HD line at 40,000 feet

Deuterium in the universe is created in the Big Bang.

Measuring the amount of cold HD (T<50K) can best be done with the ground state rotational line at 112 microns.

Detections with ISO means a GREAT high resolution spectrometer study possible.

As pointed out by Bergin and Hollenbach, HD gives the cold molecular hydrogen.

HD has a much lower excitation temperature and a dipole pole moment that almost compensates for the higher abundance of molecular hydrogen.

In the future could be used much like the HI 21cm maps but for cold molecular gas.

SOFIA will study deuterium in the galaxy using the ground state HD line at 112 microns. This will allow determination the cold molecular hydrogen abundance.

Cold Molecular Hydrogen using HD

28

10 0

10 1

10 2

10 3

10 4

10 5

10 6

10 7

10 8

1 10 100 1000

Wavelength [µm]

Sp

ectr

al r

eso

luti

on

Planetary Atmospheres

Chemistry of the cold ISMChemistry of the cold ISM

Comet MoleculesComet MoleculesDynamics of the Galactic CenterDynamics of the Galactic Center

Dynamics of collapsing protostarsDynamics of collapsing protostars

Velocity structure and gas composition in Velocity structure and gas composition in disks and outflows of YSOsdisks and outflows of YSOs

Composition/dynamics/physics of the Composition/dynamics/physics of the ISM in external galaxiesISM in external galaxies

PAH & organic moleculesPAH & organic molecules

Nuclear synthesis in supernovae in nearby galaxiesNuclear synthesis in supernovae in nearby galaxies

Composition of interstellar grainsComposition of interstellar grains

KBOs, Planet TransitsKBOs, Planet TransitsDebris Disk StructureDebris Disk Structure

Luminosity and Morphology of Star Formation Galactic and Luminosity and Morphology of Star Formation Galactic and Extra-Galactic RegionsExtra-Galactic Regions

SOFIA: Science For the Whole Community

29

SCHEDULE

30

SOFIA Schedule (Major Milestones)

• First Re-Flight Occurred April ‘07

• Door Drive Delivered Winter ‘07

• Open Door Flights at DFRC Fall ‘08

• First Science ‘09

• Next Instrument call ‘10

31

US General Observer Opportunities

• First call for science proposals in ‘09

• Future calls every 12 months

• First General Observers 2010– Expect ~ 20 General Observer science flights– Shared risk with Instrument PI’s

• Open Observatory with Facility Instruments

32

Next Call for New Instruments

• The next call for instruments will be at first Science ~FY10

• There will be additional calls every 3 years

• There will be one new instrument or upgrade per year

• Approximate funding for new instruments $8 M/yr

33

• NASA Ames and USRA are ramping up for Observatory operations. Please visit the SOFIA web site (http://www.sofia.usra.edu/) for Job opportunities.

• There will be community involvement in the Early Science Program.

• We will hold a “SOFIA’s 2020 Vision” Workshop at Caltech, December 6-8, 2007 – long term science

• We will hold a “SOFIA Early Science” Workshop at the January AAS meeting in Austin, TX, January 8, 2008

Preparations for Science Operations and Community Task Force Activities

34

Summary• Program making progress!

– Aircraft structural modifications complete

– Telescope installed, several instruments tested on ground observatories

– Completed first flight and ferry flight to NASA Dryden

– Full envelope flight testing (closed door) has started.

– Several subsystems will be installed spring/summer 08 (Door motor drive, coated primary mirror)

– First science in ’09

• SOFIA will be one of the primary facilities for far-IR and sub-millimeter astronomy for many years

35

BACK-UP

36

OPERATIONS PLANS

37

SOFIA Operations Drivers

• Frequent Flights: 960 science hours/year (2x KAO)• World wide deployments especially to the Southern Hemisphere will

be scheduled as required by science• Both Facility and PI Instruments• Facility Instruments: Good tools, Data Pipelines and Archive - easy

for non-IR astronomer to obtain good data (New for Airborne Astronomy with SOFIA)

• PI Instruments: State of the art and innovative• General Investigator program for both FSI and PI, with funded

research • Robust Instrument program to allow Observatory to “reinvent itself”

every few years• Unique Education and Public Outreach program

38

SOFIA Science Operations• SOFIA will be operated as an observatory open to the whole science

community through peer review• 3 flights a week for ~40 weeks per year• Flights will be primarily out of Dryden (Edwards AFB) with occasional

deployments to the southern hemisphere and other sites as needed– Continuous access of science and mission staff to airplane– Preflight instrument simulator facilities (testing and alignment) for mission

preparation– Instrument laboratories including cryogen facilities– Rapid instrument exchange

• Science center will be at Ames– Telescope time peer review – Observing time schedule– Flight planning– Management of Instruments (Operations and Development)– Science Data Archive(Facility Instruments Reduced data, PI raw data) – Observing Support

39

SOFIA and Spitzer

• SOFIA will become operational near the time that Spitzer runs out of cryogens. The science impact of not being contemporary is small: Spitzer is a high sensitivity imaging and low resolution spectroscopy mission. SOFIA is a high spectral and high angular resolution mission

• As it now stands, the two observatories are very complementary and when Spitzer runs out of cryogens in early FY09, SOFIA will be the only observatory working in the 25 to 60 micron region for over 10 years: Comets, Supernovae, Variable AGN, other discoveries.

40

SOFIA and Herschel

• Herschel and SOFIA will now start at about the same time

• Joint calibration work is on going

• For the years of overlap, SOFIA will be only program– with 25 to 60 micron capability– with high resolution spectroscopy in the 60 to 150 micron region

• When cryogens run out in Herschel in ~2011 SOFIA will be only NASA mission in 25 to 600 micron region for many years– Important follow-up– Advanced instrumentation will give unique capabilities to SOFIA:

Polarization, Heterodyne Arrays, Heterodyne Spectroscopy at 28 microns (ground state of molecular hydrogen), and other interesting astrophysics lines

• Both missions are critically important and complementary

41

SOFIA and JWST

• SOFIA is very complementary to JWST

• Before JWST is deployed and after Spitzer cryogens run out , SOFIA is only mission with 5 to 8 micron capabilities– important organic signatures

• After JWST is launched SOFIA is the only mission to give complementary observation beyond 28 microns and high resolution spectroscopy in 5 to 28 micron region

42

SOFIA and WISE

• WISE is a very sensitive all sky survey in the 3.3 to 23 micron region. It is expect to launch just as SOFIA begins operations.

• SOFIA can provide a number of important follow up observations.– Very red sources seen only at 23 microns can be followed up at 38

microns with FORCAST on SOFIA and spectra can be obtained with EXES on SOFIA for the brightest 23 micron sources not seen by IRAS.

– Nearby cold Brown Dwarfs discovered by WISE can be followed up with the FLITECAM GRISM and EXES.

43

Infrared Space Observatories

Ground-based Observatories

SOFIA provides temporal continuity and wide spectral coverage, complementing other infrared observatories.

Frequency (THz)

2005 2010 2015 2020 2025

SOFIA

30

3

0.3

Wavelength (µm)SPITZER

1000

100

10

1

He

rsch

el

SA

FIR

JWST

?