mcao brief overview of the mcao science case francois rigaut, jean-rené roy
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MCAOMCAO
Brief Overview of the Brief Overview of the MCAO Science CaseMCAO Science Case
Francois Rigaut, Jean-René Roy
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO
OutlineOutline
• High resolution implementation at Gemini• The MCAO Science Workshop• Strawman Instrumentation for MCAO• Excerpt from the MCAO science case:
– Numerical Simulation & analysis results – The IMF in the Milky Way– Stellar populations in nearby galaxies– Distant galaxies: Assembly, Clustering, chemical
evolution
• Work to come on Science Case for CDR
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO
An articulate AO Plan...An articulate AO Plan...
Gemini North:Gemini North:• 1999: Hokupa’a 36 (85 upgrade?) on GN• 2002: The Altair GN facility AO system• 2003: Laser on Altair increases Sky Coverage
Gemini South:Gemini South:• 2002: Possibly Hokupa’a south 85 on GS• 2005: GSAO & LGS available• 2006: MCAO available
Strong Team. Build or reinforce competence in-house.
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAOScience with MCAO: Science with MCAO: The Santa Cruz WorkshopThe Santa Cruz Workshop
• Following MCAO CoDR + 06/00 GSC, a workshop was organized to “explore the scientific opportunities for MCAO, quantify its advantages over current and planned AO systems for a comprehensive set of science cases and derive the MCAO instrument requirements”
• Organisation, preparation of science discussions led by P. Roche (Milky way), B. Schommer/ T. Armandroff/T. Lauer (nearby galaxies) and S. Morris (distant galaxies).
• Coordination: F. Rigaut/J.-R. Roy
• Modeling work: I. Baldry (AAO), C. Kobulnicky (U.Wisconsin) and E. Steinbring (CfAO) + GIRMOS studies
• Workshop Oct. 23-25, 2000 at CfAO, UCSC
– About 45 scientists from Gemini community
– Animated and open discussions
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO
The Science Case DocumentThe Science Case Document
• Build prior, during and after the MCAO workshop.• ~ 15 direct contributors + many others• Contents:
– MCAO in the Gemini instrumentation program– CAO and MCAO– I: The global mass distribution of stars -MW– II: Evolution of galaxies thru stellar pop studies– III: Evolution of distant field and cluster galaxies– Appendices
• Science case document reviewed and commented by A.Ghez, R.Davies, B.Miller, I.Jorgensen
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO
MCAO simulations, studiesMCAO simulations, studies
• Design study for MCAO deployable IFUs: sensitivities and source structures– I. K. Baldry and K. Taylor
• K band imaging with MCAO– I. K. Baldry
• A virtual observatory simulator (on line access)– E. Steinbring
• MCAO distant galaxies science: source density and emission line fluxes– H. Kobulnicky, S. Morris, I. Baldry & E. Steinbring
• GIRMOS: Operational Concept Definition Document– G. Wright & R. Sharples
• GIRMOS development studies– R. Haynes, I. K. Baldry, K. Taylor, D. Lee, et al.
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAOMultiplexing advantage and Multiplexing advantage and surface density of targetssurface density of targets
Haynes et al. 20001Proplyds/microjets in Orion
0.1T-Tauri stars
2Orion stars M<0.1 Msun
Schweizer&Seitzer 199810SSCs (B<23) ngc725
Kneib et al. 199610Grav. arcs A2218
Lowenthal et al. 19973Lyman break gals (R<25)
Fernandez-Soto et al. 19965-6HDF Irr (z=0.5-1)
Broadhurst et al. 199210All galaxies (K<20)
ReferenceN/arcmin2Object class
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAOMCAO Strawman MCAO Strawman InstrumentationInstrumentation
Nyquist sampled IMAGERNyquist sampled IMAGER
Band J H K/D [mas] 32 42 57
Pixel [mas] 16 21 29FoV (4k2) 66’’ 87’’ 118’’
• 80” field, 4k80” field, 4k22 pix, 20 mas/pixel pix, 20 mas/pixel
• ~ 4 million information points• Trade off FoV vs sampling • One plate scale !• Undersampling problems (HST) ? 80”x80”
ISS 2’ Ø hole and AO fold All images credit HST
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAOMCAO Strawman MCAO Strawman InstrumentationInstrumentation
d-IFU / GIRMOS:d-IFU / GIRMOS: • 16-32 units covering the 2’ Ø
field• ~ 0.1” “pixels”, 3” field IFUs• 1-2.5 m, R~5000 ->> Abingdon IIFlamingo II:Flamingo II: • Multi-slit spectrograph• 2.8 arcmin at F/34 (vs 2 arcmin MCAO
FoV)• Slit width down to 0.1 arcsec
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO
Actual Anisoplanatism dataActual Anisoplanatism data
23”
Typical in H band, airmass=1.7, r0~ 14cm:
Hokupa’a : 0.12” to 0.19”-> CAO : 0.042” to 0.153”
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAOStellar population: Stellar population: SimulationsSimulations
15”
Generated Stellar fields:
• GC LF
• H-K=0
• Completed down to K=30
• + HB w/ |H-K| <2
• 1/10 GC crowding
• Isoplanatic conditions as for airmass=1.5
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO
Seeing 0.65”, field 15”. 3600s. Crowded field.
AO
Seeing 0.65”, field 15”. 3600s. Crowded field.
MCAO
Stellar populations: Stellar populations: SimulationsSimulations
Seeing 0.6”, field 40”. 3600s. Crowded field.
Seeing
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO
Cut-off on W43 (rich young cluster in the galactic plane). Blum et al 1999. CTIO 0.5-0.8” over 1’2
Data reduction: B.Blum, CTIO
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO
The Quest for AstrometryThe Quest for Astrometry
• 1 mas/year = 4.5 km/s at 1kpc
• Typical V in Globulars, Open clusters = a few km/s
• Cluster partnership, mass distribution, ….• No Competition with space mission for sheer
accuracy (a few microarcsec), but (a) large field and (b) faint objects (8-m!)
• Problem = Systematics. Plate scale ~, static and dynamic distortions, detector, residual turbulence, non linearities in DM control.
• Auto-referenced method ?• Calibration scheme ? Precision and limitations?
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO
The Science Case DocumentThe Science Case Document
• I : The global mass distribution of stars -MW– Probe the bottom of the H-burning sequence and sub-stellar
distribution as a function of environment
• II: Evolution of galaxies thru stellar pop studies– Calibration of the Sne Ia Zeropoint– Stellar pop in nearby Starbursts– Evolution of dIrr vs dE– Intergalactic stars– AGB & RGB tip in Virgo/Fornax clusters– Extragalactic Globular Clusters
• III: Evolution of distant field and cluster galaxies– Internal galaxies characteristics: Kinematics /
metallicity/extinction/SFR. Field and Clusters.– Lensed galaxies, galaxy clusters
Star formation and the Star formation and the Initial Mass Function in the Initial Mass Function in the Milky WayMilky Way
• Low end of the IMF: evolution w/ environment as a tool to investigate star formation processes– determine IMF for a variety of conditions:
densities, metallicities, ages
• Orion and other star forming regions: Densities
• Open Clusters: Ages• Globular Clusters: Metallicities• Young Stellar Super-Clusters: Densities, low to
high mass ratio
P. Roche, M. Meyer, H. Richer, P. McGregor, B. Brandl, P. Puxley, D. Simons, D. Crabtree and J.-R. Roy
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAOIMF as a function of cosmical IMF as a function of cosmical time and environmenttime and environment
• Orion - imaging– M, L distribution of stars at
bottom of H-burning sequence– Explore fragmentation limit
• In Orion, 1 mJ in 1hr at H• Orion - spectroscopy
– Surface gravity (M/R) and Teff– Proper stellar atmosphere
analysis• Astrometry: 0.5 mas/yr per
km/s– Membership and masses from
binaries
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAOYoung super stellar clusters: Young super stellar clusters: 30 Dor, NGC 3603, ...30 Dor, NGC 3603, ...
IMF: Probe high mass down to brown dwarfs
• 0.4 Msun, 1 Myr K=21.5– Beat confusion: PSF of
MCAO
• Spectroscopy – Age, mass– IFU privileged sampling
aperture
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO
Instrument requirementsInstrument requirementsStar Cluster StudiesStar Cluster Studies
• Imaging – Largest field as possible (~80 arcsec)
• Edges more difficult for astrometry– Special readout time to avoid saturation of brightest
stars – Spatial resolution
• Nyquist sampled at H• Better understanding of crowding
– Faint stars vs background and foreground objects• Trade-off between sampling and field
• Spectroscopy (FLAMINGOS 2 is fine)– Slitlets for Orion: ~200 objects over 5x5 arcmin2– Dl = 0.1 mm per pointing; R = 4000 prefered
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO
Nearby GalaxiesNearby Galaxies
• Contributors: B.Schommer, B.Brandl, G. da Costa,
T.Davidge, R.Doyon, T.von Hippel, J.R.Roy, ...
• General goal: investigates star formation in a variety of environment:– Starburst galaxies
– dIrr vs d Ellipticals
– Nearby galaxy spheroids
– Extragalactic globular clusters
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO
Distant GalaxiesDistant Galaxies
• Contributors: S.Morris, M.Edmunds, I.Jorgensen, C.Kobulnicki, D.Koo, D.Schade, R.Sharples, T.Storchi-Bergmann, H.Yee, ...
• Galaxy formation and evolution:– Mass assembly of galaxies– When did the bulk of star formation occurred ?– History of galaxy clustering
• Proposed programs:– Evolution of field galaxies:
• Imaging: Morphology• Chemical evolution: metallicity/luminosity/linewidth
– Galaxy formation: Mass of galaxies at z=2– Galaxy formation in cluster– Gravitational lensing
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAOEmission lines in high z Emission lines in high z galaxiesgalaxies
The aim of MCAO spectro
-measure key diagnostic nebular lines to derive o velocities o extinction (Balmer dec) o abundances o SFR
-explore ~/> 10 objects per MCAO fields
-sample each object IFU > 10 points for gradients > 40 points for “breaks”
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAOGravitational lensing studies of Gravitational lensing studies of high z galaxieshigh z galaxies (Edmunds & Sharples)(Edmunds & Sharples)
• Exploit amplification– Spatial abundances
distribution– Resolved kinematics to study
gas flows and masses• Constrain inportance of
early strong flows and outflows
• Why?– Natural scale for strong
lensing (~0.25 Mpc) well-matched to MCAO fov
• Majority of lensed bkg galaxies lie at z = 1 – 2
• “gradient “ in z from center outward
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAOFormation of bulges/disks at Formation of bulges/disks at z=0.6 – 1.4 z=0.6 – 1.4 (H.Yee)(H.Yee)
• Understanding cluster growth/richness distribution of galaxy types– Variation of galaxy masses
• As as function of z• As function of radial distance
within cluster• Compare mean bulges and
disks to field• Strategy
– Imaging 10 clusters with MCAO and HST/ACS
– Non AO imaging with GMOS and FLAMINGOS
– MCAO spectroscopy at Ha to get rotation curves
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO
The masses of galaxies at z=2The masses of galaxies at z=2 S. Morris et al.S. Morris et al.
• Understanding assembly of building blocks of galaxies at z = 1.3 – 2.7– Rotation curves from emission
lines; R ~ 3000-5000– MCAO multiplexing (12)
• Strong drive for 2’ field• But 1.5-2.0” IFU suffice
– Serendipity spectro of Ly galaxies (1 per sq. arcmin at z=4.5)
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO……masses of galaxies: z=0.5-masses of galaxies: z=0.5-22
• Needed spectra = IFUs (~16)– Measurements of H disk rotation (50 km/s) to 1 scale
length (6 kpc: 0.’’75 at z=1)– [OII]+[OIII]/H or [NII]/[OIII] 12+log O/H
• Statistical sample requires multiplex gain– Surface density ~10 arcmin-2– 3 bins of morphology, luminosity, environment and redshift
• 10 objects per bin; >800 galaxies 30 nights
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO
From Jupiters to giant clustersFrom Jupiters to giant clusters
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAOImaging and spectroscopy with Imaging and spectroscopy with MCAOMCAO
• Imaging science cases: most convincing – Proof of astrometry to 2 mas/yr will greatly
strenghten the science case of MCAO imaging over ~1 arcmin field
• Spectroscopy with MCAO– Multi-slitlets: FLAMINGOS-2 fed by MCAO
could fulfill many key science objectives– Multi-deployable IFUs: most desirable for
distant galaxies and SSCs in nearby galaxies• Photon starved spectra
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO
Exploring very distant galaxies (z>3)
Our knowledge of high z galaxies is rest frame UV based.
Probing the rest frame optical window is crucial:- Balmer Luminosities: SFR, extinction
o compare SFR(Ha) vs SFR(UV)- 12 + log O/H abundances- Integrated widths of lines= velocity dispersion Mass
Prominent HII region lines shifted to Near-IR, but need right match of z
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO
LBG NIR spectraLBG NIR spectra
• Typically 2-hr exp. Times on Keck/NIRSEC or VLT/ISAAC
• R ~ 1500• Spectra dominated by
strong nebular lines– Little continuum
• Out of 15 galaxies, only 4 objects with sufficient S/N
Keck/NIRSPEC
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO
Spatially resolved emission Spatially resolved emission
ISAAC spectrum:
[OIII] 5007, 18000s
FWHM = 0.62 arcsec (4.7
kpc)
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO
MCAO view of z=3 galaxies will be no better than HST !
1’’ slit
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO
Multiplexing requirementsMultiplexing requirements
• To extablish a radial behavior + a central value– Monotonic gradient: 12 points with S/N > 5– Gradient with single break (rotation curve or
abundance gradient in a young barred galaxies) : ~ 48 points with S/N > 5
– Gradient with two breaks : ~ 160 points with S/N > 5
• Recent spectroscopy of galaxies at z ~ 3 from Keck/VLT (e.g. Pettini et al. 2001) shows that it is extremely challenging – However, similar studies at z=1 are feasible
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAOSpectroscopy of distant galaxies Spectroscopy of distant galaxies (z>3)(z>3)
• Recording all the lines in JHK with adequate R and S/N one full night on 8-10 m
• Even with IR MOS, assembling a sizeable sample of high z galaxies major observational effort.– Getting robust physical parameters (O/H, rotation
curves) will require 30-50m
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO……A living document: A living document: “final” version for CDR “final” version for CDR
• Develop simulation to strenghten the case for astrometry at the mas/yr level– Brent and Francois to explore further– Consult astrometrists
• MCAO spectroscopy – FLAMINGOS-2 capability at fulfilling near term
goals: Michael Meyer (Steward), Brian Miller (Gemini)
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAOSteps toward the final Steps toward the final version of the MCAO Science version of the MCAO Science CaseCase
• Establish for several science cases real fields– Put together potential MCAO fields, observing
schedule/timing (satellite interference), availability of tip/tilt stars
– Predict full field (JHK) performances and generate images/spectra
• Deadlines for “final” MCAO science case– GSC meeting of July 2001 and Board meeting
of November 2001 (updated from PDR input)– CDR in late 2002
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO
ConclusionsConclusions
• Santa Cruz Workshop triggered strong interest for MCAO across the Gemini partnership– Provided backbone to current science case– Defined several MCAO imaging cases– FLAMINGOS-2 will cover most (but not all) spectroscopy
programs • GIRMOS to be re-visited during Abingdon II
• Community endorsement of MCAO+Near IR imager • Some of the science cases require a 30-50m
telescope with MCAO• Feasibility and more quantitive work to be
completed for CDR
May 24-25, 2001 MCAO Preliminary Design Review
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MCAOMCAO
PDR AgendaPDR Agenda
Thursday, 5/240800 Welcome 0805 Project overview 0830 Science case0930 Break0945 System overview1015 System modeling1100 AO Module optics1145 Lunch
1245 AO Module mechanics1340 AO Module electronics1400 Break1415 Beam Transfer Optics1510 Laser Launch
Telescope1545 Closed committee
session1800 Adjourn