DRAFT (12/18/00) AURA’s road map to future 30m - 100m groundbased observatories - entering the “...
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Transcript of DRAFT (12/18/00) AURA’s road map to future 30m - 100m groundbased observatories - entering the “...
DRAFT (12/18/00)
AURA’s road map to future 30m - 100m groundbased
observatories- entering the “era of the
Giants” in partnership
The New Initiatives Office- a partnership between Gemini, NOAO and our
Communities
DRAFT – first thoughts (12/18/00) abbreviated version
DRAFT (12/18/00)
AURA’s “New Initiative Office”
- a New Initiative for Groundbased
Astronomy
• Global context• Science Drivers (highly abbreviated in this
version)
• Organizing for success in partnership • Focusing on Innovation
DRAFT (12/18/00)
Global context
2000 2010
NGSTNGST ALMA ALMA SIMSIM VLA-upgradeVLA-upgrade
Keck-Inter. ESO-VLTI
Keck I&II
UT1,UT2,UT3,UT4 Gemini N&S HET LBT
Phase A: of what?
OWL
201520082000 2010
CELT and maybeGSMT…
LSST?
The decade of adaptive optics
NIO timeline
The era of the “giants”
DRAFT (12/18/00)
How we will be competitive from the ground
• The “Next Generation” Space Telescope (NGST) will probably launch 2006 - 2010 – an 6m - 8m telescope in space
• NGST will be extremely competitive for:– deep infrared imaging, – spectroscopy at wavelengths longer than 3
microns
• Groundbased telescopes can still compete in the optical and near-infrared– moderate to high resolution spectroscopy
• Groundbased facilities can also exploit large baselines– high angular resolution observations
DRAFT (12/18/00)
“Deconstructing High z Galaxies”
Integral fieldobservations of a z = 1.355 irregularHDF galaxy (Ellis et al)
“Starformation historiesof physically distinctcomponents apparently vary - dynamical data isessential”
-- this is very hard on 8m – 10m telescopes
DRAFT (12/18/00)
Going beyond Gemini
JupiterSolar System @ 10 pc
500 mas
Gilmozzi et al (1998)
Lo
g1
0 F
(
Jan
sky)
m)
10 t = 10,000s R = 1800
Geminix 30
Models for 1 MJ Planets at 10 pc from Burrows et al 1997
DRAFT (12/18/00)
1 R 1 AU 100 AU 0.1 pc 10 pc
Accretion Disks
Protoplanetary Disks
Planets
Molecular Cloud Cores
Jets/HH
GMC
Mo
l. O
utf
low
s
StellarClusters
1 - 10 milli-arcseconds
Observations at z = 2 - 5
AGN
Galactic observations out to1kpc at 10 mas resolution
10 AU
Spectroscopy Imaging
100 pc
Velo
city
dis
pers
ion
R=
10
5 10
4 10
3 10
2 10
1
Flux
Going beyond 0.1 arcsecond astronomy requires resolution and sensitivity
DRAFT (12/18/00)
New Frontiers: Galaxies
Dense sampling over large fields of view:
Depth: to reach z=0.5-10 for dense sampling Capabilities
Large aperture TelescopeLarge FOV (>20’)O/IR MOS at R~5000
DRAFT (12/18/00)
Why a wide field
Sensitivity + FOV* Large Scale Structure
100Mpc (5Ox5O), 27AB mag (L* z=9), dense samplingNBT 1.5 yrGemini 50 yrNGST 140 yr
*uniqueness cf. ESO 100m OWL
DRAFT (12/18/00)
The NIO – organizing for success in partnership
Steering Committee:Pres. AURADir. GeminiDir. NOAO
Another (S.Strom)
Gemini NOAO
NIO OfficePM: J. Oschmann
PS: (TBD)NIO staff
(allocated FTE’s)
ResourcesResources
NIO AdvisoryCommittee
WorkingGroups
StudyContracts
Externalresources
AURA
DRAFT (12/18/00)
Baseline Approach - ambitious at the outset
0.9m - 3.8mTech. challenge Science challenge
• Minimize risk -- if at all possible• Focus on technologies that have the potential to produce the most innovative results
• Multi-conjugate AO• Smart structures• Optical materials and support approaches• Analytical analysis of wind-buffeting• “Cheap” enclosures
1 arcmin - 3 arcminTech. challengeScience challengeTech. challenge
• Diffraction limited telescope D ~ 30m - 100m• Operating wavelengths
• Corrected Field of View
• Uncorrected FOV 10 - 20 arcmins
DRAFT (12/18/00)
New Initiative’s Office, a partnership between Gemini, NOAO and our
Communities
• Working Groups– Science– Systems– Adaptive Optics– Optics– Structures and
Controls– Sites– Instrumentation– Management
• Issues– Corrected vs. uncorrected FOV– Error Budget, Complexity – Strehl ratio vs. FOV vs. No.
lasers– Cost of aspheric vs. spherical M1– Wind buffeting analysis, the role
of smart structures– Mauna Kea vs. Chajnantor– Narrow vs. Wide field, detectors– National vs. International
support
DRAFT (12/18/00)
Possible Concept
• A “radio telescope” married to active and adaptive optics
Mirror-to-cell actuatorsIntegrated mirror/cell segment
Large stroke actuators
Mirror support trusswith smart structureelements/active dampingas needed
Three levels of figurecontrol:
• Each mirror segment Each mirror segment is controlled within is controlled within an individual cell an individual cell• Each cell is thenEach cell is then controlled with respect controlled with respect to the primary mirror to the primary mirror support structure support structure
• The support structureThe support structure may have to use “smart may have to use “smart structure” technology structure” technology to maintain sufficient to maintain sufficient shape and/or damping shape and/or damping for slewing/tracking for slewing/tracking
DRAFT (12/18/00)
A proposed approach to achieving the image quality
science goalsLGSs provide full S.C. Deformable M2 : First
stage MCAO, wide field seeing improvement and M1 shape control
10-20’ Field at 0.2-0.3” seeing
1-2’ field fed to the MCAO module
• Wide and narrow field science multiplexing
• M2: rather slow, large stroke DM to compensate ground layer and telescope figure, or to use as single DM at >3 m. (~20000 act)
• Dedicated, small field (1-2’) MCAO system (~4-6DMs).
Focal plane
Active primary (0.1Hz)?
DRAFT (12/18/00)
How do we cost a 30 - 100m?Risk assessment examples 1 of 3• Adaptive OpticsAdaptive Optics
– multiple-conjugate AO needs to be demonstratedmultiple-conjugate AO needs to be demonstrated– requires a laser solution requires a laser solution – deformable mirror technology needs to expanded for 50m ( x deformable mirror technology needs to expanded for 50m ( x
10 - 20 more actuators10 - 20 more actuators
• How do we make “light-weight”, 2 - 4m aspheric How do we make “light-weight”, 2 - 4m aspheric segment mounted in its own active cell segment mounted in its own active cell and can we and can we afford hundreds of them?afford hundreds of them?
• How much dynamic range do we need to control cell-How much dynamic range do we need to control cell-segment to cell-segment alignment ?segment to cell-segment alignment ?
Will “smart”, and/or active damping systems have to be Will “smart”, and/or active damping systems have to be used telescopeused telescope
evaluate by analysis and test.evaluate by analysis and test. Composites or Steel?Composites or Steel?
DRAFT (12/18/00)
An Enclosure for 50m -- “how big?” Risk assessment examples 2 of 3
• Restrict observing range to airmasses < 2.0Restrict observing range to airmasses < 2.0
30 degrees75m
• ““Astro-dome” approachAstro-dome” approach• Heretical proposition #1 - excavateHeretical proposition #1 - excavate
– significantly lowers enclosure costsignificantly lowers enclosure cost– further shields telescope from windfurther shields telescope from wind– reliant on AO to correct boundary layer reliant on AO to correct boundary layer
150m 150m75m
• Heretical proposition #2Heretical proposition #2 - perhaps the wind characteristics - perhaps the wind characteristics of a site are now more important than the seeing characteristics of a site are now more important than the seeing characteristics
DRAFT (12/18/00)
Risk assessment examples 3 of 3
Telescope Structure and wind loadingTelescope Structure and wind loading We need to characterize this loading in a way that is relatively easy to use in
finite element analysis. This is easy, but mathematically intensive. Basically for each node that gets a wind force, a full vector of force cross spectra is generated, therefore the force matrix is a full matrix with an order equal to the number of forces (10’s of thousands).
Enclosure concept (do we need one)?Enclosure concept (do we need one)? What concept can we afford both in terms of dollars/euros What concept can we afford both in terms of dollars/euros and and
environmental impact environmental impact (note Heretical Proposition #2)(note Heretical Proposition #2)
PROBABLE CONCLUSION: WE NEED A TECHNOLOGY PROBABLE CONCLUSION: WE NEED A TECHNOLOGY TEST-BEDTEST-BED a 20m - 30m “new technology telescope”a 20m - 30m “new technology telescope” this is probably to only way to establish a credible this is probably to only way to establish a credible
cost for a 50m - 100m diffraction limited optical/IR cost for a 50m - 100m diffraction limited optical/IR groundbased telescopegroundbased telescope
DRAFT (12/18/00)
New Initiative’s Office, a partnership between Gemini, NOAO and our
Communities
• Working Groups– Science– Systems– Adaptive Optics– Optics– Structures and Controls– Sites– Instrumentation– Management
Preliminary reportsin draft form, community meetingsand first design studiesunderway- Strategy Document by June 2001