tmt on la palma or maunakea
TRANSCRIPT
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TMT on La Palma or Maunakea. Construction status.
Assessment of alternate sites.
Prepared by TMT DEOPS Team For TMT ISDT members
Version date: May 26, 2017 TMT.OPS.PRE.17.009.REL01
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! ObservatoryConstruc0onPhaseUpdate! Technicaldevelopment! Theneedtoiden0fyasiteandbeginconstruc0on
! AssessmentofAlternateSitesandtheDecisionProcess! Solicita0onofproposals! Abilityofpoten0alsitestosupportTMTscience
! Sitecharacteris0csandsystemperformance! ThemajoreffortofDEOPSgroupwithAOgroup
! Keyresults! Availableobservingmodesandabilitytosupportscience
! ORMsupportsTMTscience,construc0onandopera0ons
Overview of Talk
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Technical development Allcri0calsystemsinconstruc0onorfinaldesignphasesDevelopmentproceedinginallareas
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The need to begin on-site construction
! On-siteconstruc0onisdomina0ngthecri0calpathitemsintheprojectschedule
! Projectfundingisdependentonfollowingacertainpacing
! UncertaintyaboutpermiIng0mescalesandsiteaccessforMaunakea
! Necessarytoevaluatealternateop0onsforasiteforTMT
! ThesitemustsupportthesciencegoalsforTMT
! Thesitemustsupport0melyconstruc0onandopera0ons
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Assessment of Alternate Sites and the Decision Process
! Solicita0onofproposals! On-siteconstruc0onmustbeginbyApril2018
! BoarddecisionplannedOctober2017! Followingvaca0onofHawaiiCDUP(Dec.2015)acallforproposalstohostTMTwascirculated(Feb.2016)! Proposalsincludedsitecharacteris0cs,logis0calandprogramma0cinforma0on
! Poten0alsitesaYersolicita0onsreceived:! India(Hanle)! China(Ali)! Mexico(SanPedroMar0r)! CanaryIslands(ObservatoriodelRoquedelosMuchachos)! Chile(MackennaandHonar)
! Ini0alexamina0onandfirstdownselect! DuetoremotenessbothHimalayansiteshadverysignificantlogis0calconcernsandwhilstgenerallyverygoodsites,theywerelessabletosupportthespecificTMTScienceCasesthantheothers
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Assessment of Alternate Sites and the Decision Process
! Furtherinves0ga0onsofsitecharacteris0cs! LargeeffortbytheTMTDEOPSgrouptodevelopaconfidentunderstandingofthecharacteris@csofpoten@alsites
! Maintaskswereinforma0ongatheringandanalysis! Short0mescaledrivenbydeadlinefordecision(Oct.2016)! No0meforaddi0onalsitetes0ng–Usepre-exis0ngsourcesofinforma0on
! Crosschecksofallresultsfromindependentdatasets! Inves0ga0ngconcernsanddevelopingdataproductstoallowperformancemodelingandscien0ficproduc0vitytobeevaluated
! Alsosolicitedadetailedclimatechangestudy! Parallelexamina0onofcost,schedule,technicaland
logis0calissuesbyprojectmanagement,projectteamsandsub-groupofTMTboard–Verysignificanteffort
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Sources of Information Site Seeing/
turbulenceWind PWV Clear
frac@onNight@metemperature
Skybrightness Transparency Groundleveldust
Rela@vehumidity
Mirrordegrada@on
ORM RawdataIAC,ESO,NOAA,WHT/CANARY.InternalTMTanalysis
IAC Guimarsta0onradiosondesoundings.IACGPS.InternalTMTanalysis
CMTlogs,Garcia-Gilletal.,2010
IAC,NOT SteidelObs.(M.Pedani,2004,NewAr)
RawdataCMT.InternalTMTanalysisPlusLT,StetsonObs,SteidelObs.
RawdataTNG.InternalTMTanalysis
RawdataNOT.InternalTMTanalysis
GTC,LT,Geminidevelopment,CTAtes0ng
SPM TMTSitetes0ngforCerroPelado,SPM
TMTSitetes0ngforCerroPelado,SPM
TMTSitetes0ngforCerroPelado,SPM
TMTSitetes0ngforCerroPelado,SPM
TMTSitetes0ngforCerroPelado,SPM
- SchusterW.,ParraoL.&GuichardJ.,2002
TMTSitetes0ngforCerroPelado,SPM
TMTSitetes0ngforCerroPelado,SPM
CTAtes0ng
Honar TMTSitetes0ngforTolonchar
ChajnantorPlateau,Perez&Otárola,2004
ExtrapolatedfromChajnantorPlateau(Giovanellietal.,2001)
ErasmusstudiesandGiovanellietal.,2001
ExtrapolatedfromCBITelescope
- - TMTSitetes0ngforTolonchar
TMTSitetes0ngforTolonchar
-
Mackenna TMTSitetes0ngforArmazones
TMTSitetes0ngforArmazones
TMTSitetes0ngforArmazonesandLakicevicetal.,2016,Kerberetal.,2014,Otarolaetal.,2015
TMTSitetes0ngforArmazonesandParanalASCAM
ExtrapolatedfromTMTSitetes0ngforArmazones
Paranalsitemeasurements
Patat,F.,2004
TMTSitetes0ngforArmazones
TMTSitetes0ngforArmazones
CTAtes0ngforArmazones
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Assessment of Alternate Sites and the Decision Process
! Sitecharacteris0cs! Compara0veresults
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Assessment of Alternate Sites and the Decision Process
♯FromIMACSuserguide§MedianvalueforArmazones,TMTsitetes0ng$0.132exc.Mt.Pinatuboerup0on
! Sitecharacteris0cs! Compara0veresults
Sitecharacteris@cs(medianvalues,unlessstated)
MKO(USA)
ORM(Spain)
LCO(Chile)
Al@tudeofsite(m) 4050 2250 2500Frac@onofyearlyusable@me(%) 72 72 75Seeingat60maboveground(arcsecond) 0.50 0.55 0.50Isoplana@cangle(arcsecond) 2.55 2.33 2.05Atmosphericcoherence@me(ms) 7.3 6.0 5.0PrecipitableWaterVapor(%of@me<2mm) 54 ≥20 23Adap@veOp@csStrehlmeritfunc@on 1.0 0.93 0.92MeannighWmetemperature(oC) 2.3 7.6 13.0Ex@nc@on(Vmag/airmass) 0.111 0.137$ 0.14♯
Grounddustconcentra@on(µg/m³) 0.815 1.006 2.289§
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Assessment of Alternate Sites and the Decision Process
! Sitecharacteris0cs! Keyresultsandexamples
! Groundleveldust! MirrorDegrada0on! Usable0me! Ex0nc0on! PWV! Op0calTurbulenceandLaserGuideStarOpera0on
! Publicdocumentsandinforma0on! hop://www.tmt.org/observatory/site-informa0on/alternate-site-studies
Significant funding provided by the Gordon and Betty Moore Foundation
Thirty Meter Telescope
Site Locations
ALTERNATE SITE: OBSERVATORIO DEL ROQUE DE LOS MUCHACHOS
December 2016 www.tmt.org
Alternate Sites
STUDIES
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Atmospheric Turbulence and
Laser Guide Stars
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! Sitetes0nghasbeengoingonfordecadesatORM! Lotsofdifferentdatasetsavailable! Nolong-0meMASS/DIMMdatasetfordirectcomparisonwithotherTMTsites
! Becauseweneedthe60-mseeing,weneedtoworkwithturbulenceprofiles! DIMMdataareonlyusedfor(successful)consistencychecks
! Bestavailabledataset:SCIDARdatacovering>5years,almost200,000datapoints! ScidarprofilesareactuallymoreaccuratethanMASSprofilesforAOperformance
analyses(becauseofthehigherver0calresolu0on),butweneedtocomparetoMASSdatafromothersites➞reduceSCIDARdatatoMASSresolu0on
! Comparisonwithothersitetes0ngdatasetsandAOperformancefromobservatoriesareallconsistent
! Usingsameextrapola0onto60mseeingasforMaunakea13N! Thisisdoneonapoint-by-pointbasis,assemblingsta0s0csaYerward
! Butusingsta0s0csgivesalmostiden0calresults(yes,weverifiedallofthat)! Alldistribu0onsveryclosetolog-normaloncesufficientdataareavailable
! N.B:Accuracyof(highquality)turbulencemeasurementsisorder10%
ORM Turbulence Data
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! Isoplana0cangle:SCIDARprovidesreliablees0mate! GLdoesnotmaoeratall! WeuseMASS-resolu0onprofilesfromSCIDARsforcomparisonwithothersites
! Thereisnoques0onthatthecoherence0meislargeatORM
! Thishasbeenshownoverandoveragain! 200mbarwindspeed(seebackupslide)! Weakhigh-eleva0onturbulence! Consistentwithexis0ngmeasurements
! No0meseriesofτ0measurementssimultaneouswithSCIDARprofilesavailable
! Usinges0mateofaverageτ0forallprofilesforAOperformancesimula0ons! Someuncertaintyonexactvalue,but:
! ExpectedtobelongerthanattheChileansitesandslightlyshorterthanatMaunakea! Sensi0vityand“inverse”analysesshowthatthishasasmalleffectonNFIRAOS
performance! 6msisaconserva0vees0matecomparedtoothersites
Isoplanatic Angle and Coherence Time
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Laser Guide Star Operation
! ModelingofLGSperformanceincludedex0nc0onandscaoeringeffects! RayleighScaoering,O3ChappiusBand,Cirruscloudicepar0cles,ex0nc0onandscaoeringduetodust(aerosols)
! Cirrusathigheral0tudecausesmorebackscaoeringthandustatloweral0tudesforthesamelevelofex0nc0on
! Ex0nc0onatORM(regardlessofcourse)hassamesta0s0csasex0nc0onatMK13N
! ConclusionisthatdustatORMwillnotsignificantlyaffectLGSopera0on
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Dust. Usable Time. Extinction.
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Sources of ground level dust measurements
! MK13N,Tolonchar,SPM,Armazones! ~2.5yearsateachsite! Measurementsevery5to7minutes! Commercialdustsensorat7m
! ORM! 9years5monthsofmeasurements! Measurementsevery2hours! Externalinletat11monTNGenclosure! Commercialdustsensor(differentmodelbutsamespecsasabove)
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Dustmassconcentra0onprobabilitydistribu0on(Dustmasscalculatedfrompar0clesizedistribu0on)• ORMandMK13Nhavelowesttypicaldustlevels
TMT.PSC.TEC.16.007.DRF01 Page 38 of 51 ASSESSMENT OF ALTERNATE SITES FOR TMT, METHODS AND RESULTS
October 13, 2016 Table 18: ≥15 µg/m3 is considered a dust event at ORM9, the GTC cleans mirrors in response. If the level reaches 50 µg/m3 and continues rising the LT prepares to close. 100 µg/m3 is the GTC and LT operational limit.
Fraction of time exceeding Site Median µg/m3 ≥15 µg/m3 ≥50 µg/m3 ≥100 µg/m3 ORM 1.006 11.5% 2.3% 0.54% MK 13N 0.815 6.8% 3.6% 2.4% SPM 7.02 26.8% 13.9% 4.4% Armazones 2.29 5.4% 0.41% 0.32% Tolonchar 6.30 24.7% 8.9% 2.1% Tolar 3.38 13.1% 0.30% 0.11%
The ORM observatories close when dust levels reach unacceptable levels, typically the closure limits are 100 µg/m3. To explore the operational issues related to the fractions of time the dust levels were above various thresholds were calculated for all sites, these are shown in Table 18. Figure 14 shows zoomed in portions of the dust mass concentration time series for the TMT candidate sites. A common misconception is that only ORM is seriously affected by the presence of dust. In Figure 14 it is evident that the dust levels at sites other than ORM are not necessarily any better and Table 18 quantifies the occurrence of various dust levels. Surprisingly, the occurrence of dust levels >100 µg/m3, the shutdown level for the GTC and LT at ORM, is 4 times more common at Maunkea 13N than at ORM, 4 times more common at Tolonchar and slightly more frequent than at Tolar and Armazones (at a level <<1%).
Figure 12: Red dots show the correlation between the two methods for estimating the dust mass from the dust particle size distribution (measured dust refers to the 9 Some works suggest that 20 µg/m3 would be considered a dust event; Chiapello et al. 'Detection of mineral dust over the North Atlantic Ocean and Africa with Nimbus 7 TOMS', J. Geophys. Res., 104, (1999), p 9277-9291
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Ground level dust concentrations
Dashedlinelevelconsideredas‘anevent’atORM(15μg/m3)
DashedlineshowsORMclosurelevels(100μg/m3)
• ORMandMK13Ntypicallyhaveverylowdustlevels• Allsiteshaveepisodesofhighdustlevels
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Mirror degradation
! Geminites0ngatPachon! BareAllost0.03%/day,protectedsilver0.06%/daywithoutanycleaning
! Bothrestoredto100%aYerwetcleaning–nosurfacedegrada0on! CTAtes0ng(overcoatedAlatSPM,Armazones,Teide)
! %/day–0.015(SPM),~0.02(Armazones),~0.01(Teide)! Liverpooltelescope(bareAl)experienceatORM
! 0.1%/dayinbetweenCO2cleaning,0.04%onaveragewithCO2cleaningon6week0mescale–samerateasothersites
! GTC(bareAl)experienceatORM! CO2cleaningproceduresensurenoaddi0onalmirrordegrada0onduetodust
! “Theimpactonopera0onsofgroundleveldustatORMismuchlessofaconcernthananecdotalreportswouldleadonetobelieve.”-TMTInternalreport(W.Skidmore,etal.)
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Usable Time ! Usable0meatORMises0matedfromobservatoryweatherlosssta0s0cs
! Shutdowncondi0onsaredifferentfromobservatorytoobservatory(incl.TMT)
! Usable0meforTMTatORMwilllikelybesimilartothelargetelescopesthere,i.e.,inthe70-74%range(using72%inSMF)
! Corroboratedby“manual”analysisof5yr1monthofCMT(ATC)observinglogswhichagreeto<2%withvalueintableabove(19.1%vs.20.7%)
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Usable Time
! “Clearfrac0on”fromtheErasmussatellitestudies! Satellitedatacoverlongerperiodsthanon-sitemeasurementsatthesites! Satellitemeasurementsextensivelyvalidatedusingon-siteall-skycamera
(ASCA)andMASStransparency,weathersta0on)! Addi0onal0melostcomesfromsimultaneousASCAandweathersta0on
measurements! Useofsatellitedatameansthatwehaveequivalentdataforallsites! Rela@veprecisionforcomparingsitesin2008reportis5%orbe^er
Clear Fraction
Additional time lost due to weather
Usable Time Best Estimate
ORM 72% SPM 82% 2% 80% Armazones 89% 3% 86% MK 13N 76% 4% 72% Tolonchar 82% 3% 79%
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Extinction
ModelsbyChuckSteidel(Consistentwithhiscalibra0onmeasurementsatORMandMK)nMedianex0nc0onlevelsfrom10yearsofnightlyphotometriccalibra0onmeasurementsfromLiverpoolTelescope✕0.132mags/airmassfrom30yearsofCMTmeasurements,excludingthepartofhighex0nc0onduetoMountPinatuboTriangleisVbandex0nc0ononGeminiNorthwebsiteof0.12mas/airmass
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C.Butonetal.,2013
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Precipitable Water Vapor Site ORM SPM Paranal
(Mackenna) Maunakea Honar
Al0tude 2250m 2830m 2640m 4050m 5400m
<2mm 20% 26% 44%(50%)
54% 76%
5% 1.02mm 1.06mm 0.81mm 0.59mm 0.16mm
10% 1.42mm 1.29mm 0.99mm 0.78mm 0.23mm
20% 2.00mm 1.74mm 1.32mm 1.03mm 0.34mm
25% 2.20mm 1.96mm 1.46mm 1.15mm 0.40mm
50% 4.24mm 3.12mm 2.26mm 1.91mm 0.80mm
75% 7.03mm 6.12mm 4.04mm 3.54mm 1.74mm
95% 12.2mm 15.15mm 9.58mm 8.15mm 5.12mm
ORMPWVderivedfromRadioSondemeasurements.PublishedGPSmeasurementsbelievedtobeunder-es0mate.<2mmvalueforMackennaes0matedasevidencesuggestsPWVscaleheightis>1.8kmatgroundlevelbutdoesn’tprovidequan0ta0vevalue.
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Climate Change
! Dr.EddyGraham! HadleyCellsaremovingandexpanding
! Noevidencethatchangeswillaffectthepoten0alTMTsites
! Someotherexis0ng/poten0alsitesmaybeaffected! Equatorialregionsbecomingpoorerhigh/lowerla0tudesimproving
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TMT Climate Study Contract No. TMT.BUS.CON.16.___.REL01
Final Report
This document version: 1.0 This version supersedes any earlier version. Date: 16 October 2016
Dr. Edward Graham (FRMetS) Meteorologist and Climatologist @eddy_weather Scotland
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Available observing modes and ability to support science
! Abilityofpoten0alsitestosupportTMTscienceTMTpoten@alsites
Al#tude(m)
MKO(4050)
ORM(2250)
SPM(2790)
Chile#1(5400)
Chile#2(3110)
%ofusable0meforscience 72 72 80 79 86
Sciencecases
Visiblespectroscopy/imaging WFOS
UV/VisibleHRspectroscopy WFOS
Near-IRAO IRIS/NFIRAOS,PFI
L/M/Nbandobserva0ons MICHI
Q-band MICHI
Maincharacteris@csPros
(Benchmark)AOperf. %clear@me UV/Mid-IR %clear@me
Cons Mid-IR Mid-IR Weather N/A
SiteM
erit
Func@o
n
Visible 1.0 0.9 0.9 1.1 1.2
Near-IR 1.0 0.8 0.8 1.1 1.0
Mid-IR 1.0 0.2 0.3 2.6 0.8
[40%Vis.,50%Near-IR,10%Mid-IR]Total 1.0 0.8 0.8 1.2 1.0
(notTMTcore-science)
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Assessment against science cases
Color coding(sensitivity wrt MKO): Better Identical Acceptable Compromised Important loss Target problems (loss of targets, or challenging observing conditions due to site latitude)
New science cases from 2015 DSC
Observing U.S.A. MEXICO SPAINWavelength Spectral Image MKO SP.Martir vs MKO R.Muchachos vs MKO Honar vs MKO V. Mackenna vs MKO
(µm) (λ/Δλ) Resolution (mas)
Strehl (S) / Contrast (C) ratio (4050m) (2800m) (2250m) (5350m) (3100m)
100% 108% 99% 105% 117%
Dwarf galaxy SL 0.51-0.535 >20,000 10000 WFOS All sites+/- equal at these Dwarf galaxy MCAO 2 - 2.4 6 10 (20) > 0.3 (20) 10000 (20) 100-1000 (20) Ideally WIRC, IRIS All sites+/- equal at
Baryonic SL 1000(2) 280000 (2) 1000 (2) WFOSBaryonic SL 5000 (2) 12800(2) 80(2) WFOSGalactic MCAO 2 - 2.4 > 3000 (23) < 15 (23) 100 120 Ideally IRIS but WIRC Galactic Center science
Lyman-alpha SL 0.35 - 0.62 1000 - 5000 800 (2) 12800 - 80 - 1000 (2) WFOS, same Low altitude sites loose Supernovae MCAO 1.5 - 1.7 (21) 4000 (21) 250 (21) 250 (21) 250 SNIa at 1 < z < All sites+/- equal at these
SL 0.30 - 0.90 7500 (17) 700 (17) WFOS Low altitude sites loose MCAO 0.97 - 1.8 (16) 30000-50000 NIRES All sites+/- equal at these
Supernovae SL/MCAO (18) 0.3 - 2.5 (18) 1000-5000 200 - 500 (18) 40 - 250 (18) WFOS/IRIS Low altitude sites loose Tidal flares SL 0.30 - 0.90 7500 (17) 700 (17) 2000 2000 WFOS Low altitude sites loose
SL 0.49-0.59 (3) 50000 (3) 700 (3) 50 (3) 50 (3) HROS All sites+/- equal at **NEW DSC** Dark Matter MIRAO MIR >300 ~4 ? MICHI IFU or Imager All low altitude sites have
Primordial MCAO/MOAO 1.6 - 6.0 3000 (8) 25 (10) 25 - 250 25 (10) IRMS/IRMOS/IRIS Thermal-IR sensitivity Characterizin MCAO/MOAO 1.1 - 1.6 3000 (8) IRIS/IRMOS All sites+/- equal at these Topology of MOAO 0.8 - 2.5 (10) ~3000 25 (10) 150 - 1500 (10) 150 (10) IRMOS, R=10Mpc All sites+/- equal at these
MCAO 0.9 - 1.3 30000 NIRES All sites+/- equal at these
SL 0.31 - 1.0 5000 (17) 800 (17) 100 (17) 8 (17) WFOS Low altitude sites loose MCAO/MOAO 1.0 - 2.5 3270 200 100's 10's IRMS/IRMOS All sites+/- equal at these MCAO/MOAO 1.0 - 2.5 4800 8 S = 0.5 (7) 1400 (10) < 140 (10) IRIS/IRMOS All sites+/- equal at these
SL 0.31 - 0.60 5000 800 (17) 15000 100 WFOS w/ HROS follow-Low altitude sites loose SL 0.32 - 0.65 500 800 (17) 120000 1000 WFOS w/ IRMOS Low altitude sites loose
MCAO/NGSA 0.8 - 2.5 (8) 4000-8000 10 (7) S = 0.5 (7) 340 (7) 340 (7) IRIS, sample size is MCAO/NGSA 0.8 - 2.5 (7) 3000 (8) 8 - 10 (7) S = 0.5 (7) 90 (22) 180 (22) IRISMOAO/MCAO 0.8 - 2.5 (11) 4800 (11) 50 (11) S = 0.5 (11) 1200 (11) 35 (11) IRMOS/IRIS All sites+/- equal at these
SL 0.33 - 0.9 (3) 40000 700 (3) 100 100 HROSSL 0.45 - 0.68 90000 700 (3) HROSSL 0.33 - 0.9 (3) 50000 500 (3) HROS
MCAO 1.4 - 2.4 (16) 40000 (16) NIRES - molecular Diffusion SL 0.55 - 0.69 HROS - abundances Mass loss SL 0.4 - 0.7 WFOS - brightest
MCAO 1.0 - 2.5 4000 10 - 30 (20) S = 0.6 (7) 2500 / obs (20) 50 / galaxy IRIS/WIRC
Initial mass MCAO 1.0 - 5.0 (8) 4000 15 S = 0.5 (7) IRIS IFU w/ Structure and MIRAO 4 - 5 (15) 100000 80 100 (15) 100 (15) MIRES/NIRES
Gas MIRAO 4 - 25 (15) 30000 - 300 (15) 300 (15) MIRES/NIRES All low altitude sites have Gaps MIRAO 4 - 13 (15) 100000 400 400 MIRES/NIRES All low altitude sites have
Pre-biotic MIRAO 18 - 25 (15) 100000 (15) 100 (15) 100 (15) MIRES All low altitude sites have
Planets SL 0.48 - 0.62 50000 (3) 700 (3) 100's 100's HROSTerrestrial MCAO 0.97 - 1.7 (16) 50000 - S = 0.3 - 0.6 (16) 400 400 NIRES
Self-luminous ExAO 1.63 (14) 5 (14) 30 (14) S = 0.9 (14) 100's (14) 100's (14) PFI All sites+/- equal at these Reflected ExAO 1.63 (14) 5 (14) 50 (14) S = 0.9 (14) 1900 (14) 1900 (14) PFI All sites+/- equal at these **NEW ExAO 5-10 mic High-contrast / All low altitude sites have Jovians ExAO 1.1 - 1.8 (14) 50 - 100 (14) 50 (14) S = 0.9 (14) PFI/IRIS All sites+/- equal at these Jovians SL 0.5 - 0.9 50000 700 (3) HROS
Oxygen on SL 0.76 - 0.77 40000 700 (3) < 2500 < 2500 HROS**NEW ExAO 5-10 mic High-contrast / All low altitude sites have
Kuiper Belt MCAO/NGSA 1 - 2.5 1000 7 (19) S = 0.3 (19) 1092 (19) 1092 (19) IRIS/WIRC All sites+/- equal at these Composition MCAO/MIRAO 3 -5 (16) 100000 (16) 27 (16) 100 (16) 100 (16) NIRES Thermal-IR sensitivity
MCAO/NGSA 0.8 - 2.5 (19) 2000 7 S = 0.7 (19) 25 (19) 25 (19) Program includes All sites+/- equal at these MIRAO 10 100000 (15) 80 MIRES All sites+/- equal at
M31 / M33 are not visible from Southern
Formation of stars and planetsDSC 8
Ratio of clear nights (wrt MKO)
Low altitude sites loose sensitivity towards short
Our Solar SystemDSC 10
Outer Solar System
Surface physics of Jovian Atmospheric physics of
Direct detection and characterizati
ExoplanetsDSC 9
Doppler detection of
Physics of star
Protoplanetary disksDSC 8.3
Multiplexed spectroscopy of Spatial dissection of forming IGM: Core samples during
Epoch of galaxy formation in
Chemical evolution in the Local Group galaxies and
SMBHs in nearby galactic
Stellar astrophysics
Reconstructing star
Exploration of nearby galaxiesDSC 7
Probing oldest stars in the Looking deeper: isotope
SMBHs at very high redshift
Gamma-ray bursts
Variation of fundamental
Science Program
Nature of Dark Matter
DSC 3.1
Extragalactic SuperMassive Black Holes
Early UniverseDSC 4
First GalaxiesDSC 4.3
Dark energyDSC 3.2
Physics of extreme objectsDSC 3.3
Intergalactic medium
0.35 - 0.62 (2) 800 (2)
Sample Size Comments# of observation
s
Comments
Southern sites mean loosing Kepler targets but
Southern sites mean loosing Kepler targets but
SL/NGSAO/ MCAO/
MOAO/MIRAO/ExAO
Spectral Parameters Spatial Parameters Multiplexing
600600
Differential impact of alternative sites wrt MKOCHILE
Galaxy Formation
and Intergalactic
medium
Multiplexed spectroscopy of
(Exo-) Planetary
atmospheres
SMBHs beyond local
Note: (1) UV and near-IR sensitivity impacted for low altitude sites. (2)
Southern sites mean loosing M31 and other
N.H. galaxies but getting access to Magellanic
Fundamental Physics and CosmologyDSC 3
M31 / M33 are not visible from Southern
AllalternatesitesareabletosupportTMTkeyscience
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Assessment of Alternate Sites and the Decision Process
! Siteevalua0onwasamul0-dimensionprocess:! Astronomicalproper0esofthesites–AbilitytosupportTMTscience! LegalstatusforTIOtooperateinthehostcountry! Processesand0mescalesforobtainingnecessarypermits,scheduletostartconstruc0on! Costtoconstructandoperate! Anevalua0onoftheriskstoscheduleandcost.
! Oct.31st2016,TIOBoardselectedORMasthealternatesiteforTMT.Considering:! Thescien0ficimportanceforTMTtobeuniquelylocatedintheNorthernHemisphere,securingfullskycoverage
incombina0onwiththeELTprojectslocatedintheSouthernHemisphere.! TheverygoodqualityoftheORMsite,whichcansupportTMTcorescienceprograms
! Inpar0culartheturbulenceproper0esandcapabili0esforAOperformance! Theprogramma0cadvantageswiththeORMsiteincluding:
! Shorter0melinetoini0ateconstruc0on! Shorter0melineto‘first-light’! Lowercostsofconstruc0onandopera0ons! Lowerprojectrisksbasedonexistenceofsupportinfrastructure
! ORMisthebestsiteamongallalternatesitesconsidered,tosecureacompe00vepathtofirst-lightwithintheTMTbudgetenvelope
! Lower-al0tudesiteslikeORMsufferfromlowersensi0vityatlongermid-IRwavelengths,hencelowerefficiency! Opera0onsschedule(technicalandscien0fic)willbeflexibletoop0mizebestcondi0onsfordemanding
scienceprograms! Revisi0ngthepriori0esforTMTnextgenera0oninstruments
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Adjusted operations
! ORMopera0onsmodelsimilartoMKO! Maintenancecrewtravelingdailytosummit! Scienceopera0onsdoneremotelyfromscienceHQ(Tenerife)andTIOsciencenodes
! Toop0mizescienceefficiency,flexibleschedulingofscienceandengineeringac0vi0esisneededatanysite! ExtraemphasisisneededatORMtou0lizethebestcondi0onsforthescienceprogramsthatneedthem! SCMStoincludePWVmonitoring(collabora0onwithIAC)! Requiresaddi0onalsoYwaredevelopment(wrtcurrentplan)toop0mizereal-0mepriori0za0onofprogramscheduling/execu0on
! Instrumentpriori0estoberevisited
Prepared by TMT DEOPS
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Any questions?