Download presentation
Presentation is loading. Please wait.
Published byEgbert Lane Modified over 9 years ago
1
AO4ELT - Paris 20091 Giant Magellan Telescope Project Science Drivers & AO Requirements Patrick McCarthy - GMT Director Phil Hinz & Michael Hart - GMT AO Team AO4ELT - June 22, 2009
2
AO4ELT - Paris 20092 The GMT Partners US Institutions Carnegie Institution Harvard University Smithsonian Institution Texas A&M University University of Arizona University of Texas Austin International Institutions Astronomy Australia Limited Australian National University Korea Astronomy & Space Science Institute
3
AO4ELT - Paris 20093 The GMT Concept Giant-Segmented Mirror Telescope 10mas @ 1μm 380 sq. meters f/8 Gregorian Segmented Adaptive Secondary Natural Seeing 20 FOV Ground-Layer Correction 8 FOV Diffraction-limited 20 - 40 FOV
4
AO4ELT - Paris 20094 Gregorian Instrument Mounting Survey, GLAO, & Mid-IR instruments below LTAO instruments above
5
AO4ELT - Paris 20095 Instrument Platform Top Layout Natural seeing instruments AO relay AO instruments GLAO/LGS wavefront sensors 10 m 16 m
6
AO4ELT - Paris 20096 Gregorian Instrument Rotator GLAO & Mid-IR Instruments Instrument platform (IP) Multiple instrument mounting
7
AO4ELT - Paris 20097 Instrument Development GMT Instrument ConceptsMode λ specification (microns) High resolution near-IR camera LTAO1.0-2.5 High contrast Mid-IR AO imager NGSAO1.2-2.5 & 3-5 Near-IR echelle spectrograph AO & NS0.9-5 High resolution optical spectrometer NS0.34-0.90 Wide-field multi-object near-IR spectrograph GLAO1.2-2.5 Wide-field multi-object optical spectrograph NS0.34-0.9 Near-IR integral field spectrometer LTAO1 – 2.5 Mode: AO = adaptive optics, NS = natural seeing NIRMOSGMTNIRSGMACS
8
AO4ELT - Paris 20098 AO Science Drivers Exoplanet Studies Imaging exoplanets in reflected light Thermal radiation from young exoplanets Structure of debris disks Stellar Populations IMF variations Star Formation Histories Black Hole Demographics Galaxy Assembly Structure & Dynamics of Galaxies at z > 2 First Light Studies
9
AO4ELT - Paris 20099 L band detection limit 16x improved with ~4x larger diameter 3.8 um: 25 Jy10 um: 750 Jy 3 λ/D: 0.48”3 λ/D: 1.0” 3.8 um: 1.5 Jy10 um: 45 Jy 3 λ/D: 0.11”3 λ/D: 0.25” Detect 5-10 M J giant planets 100-300 zody warm debris disks Detect <1 M J planets 3-10 zody warm debris disks 1 hour 5 sigma limits Mid-IR Imaging of Exoplanets GMT can undertake comprehensive study of giant planets in > 3 AU range around stars at 30 pc. HR8799 MMT
10
AO4ELT - Paris 200910 Nascent Planetary Systems JWST GMT ALMA JWST GMT 10 AU Pic at 11 m Gemini ELTs have the spatial resolution to probe the zone where Earth-like rocky planets live
11
AO4ELT - Paris 200911 Globular Cluster around Cen A 3.8Mpc 3pc core radius H-band HST GeminiGMT 2 4mas pixels Laser Tomography Adaptive Optics Resolving Distant Stellar Systems with AO
12
AO4ELT - Paris 200912 Resolving Distant Stellar Systems with AO Gemini 8m GMT 25m Globular Cluster around Cen A 3.8Mpc 3pc core radius H-band
13
AO4ELT - Paris 200913 UDF 6462, H-band, NIFS, Hα z = 1.57, M B = -21.0, 5 hr object, 5 hr sky HUDF - i NIFS - Sum Clump cluster
14
AO4ELT - Paris 200914 UDF 6462, H-band, GMTIFS, Hα z = 1.57, M B = -21.0, 5 hr object, 5 hr sky HUDF - i GMT - Sum Clump cluster
15
AO4ELT - Paris 200915 Image Sharpening with GLAO 15 x 15 60 mas pixels 0.5 FWHM0.15 FWHM The GMT architecture is ideally suited for Ground-Layer AO Native Seeing GLAO
16
AO4ELT - Paris 200916 Adaptive Optics Prioritization Three guiding considerations: 1. The AO system should allow us to meet our science goals 2. It should build on the natural strengths of the GMT - low thermal IR foot print - ground-layer conjugation with wide-field of view - clean diffraction pattern 3. A clear upgrade path that uses much of the first generation hardware
17
AO4ELT - Paris 200917 AO Science Targets TargetsRequirements Exoplanets, debris disks,Diffraction-limited images & IFU Spectra AGN, black holessmall sizes, low sky density, no multiplexing High Strehl, small field, low-background - Laser Tomography (LTAO) & NGS AO z > 2 galaxiesRange of sampling scales, IFU & slit spectra small sizes, moderate sky density All-sky, range of Strehl, range of field, near-IR only - GLAO & LTAO Resolved stellar populationsDiffraction-limited, emphasis on photometry range of sizes, low sky density All-sky, high Strehl, large field - LTAO & MCAO
18
AO4ELT - Paris 200918 ModeDescription Laser tomography AO (LTAO) “All-sky” high Strehl - Sodium beacons adaptive secondary is DM Ground Layer AO (GLAO) “All sky” - Sodium beacons factor of 2-4 image size reduction, 9′ FOV Adaptive secondary conjugates to ground-layer Natural Guide Star AO (NGSAO) High Strehl - natural guide stars within the isoplanatic patch Multi-Conjugate ~1′ diameter field, diffraction-limited, uniform PSF 12km conjugate DM in AO relay Extreme AO (ExAO) High contrast, high Strehl for exoplanet detection tweeter DM in instrument First Generation GMT AO Modes
19
19 AO Features Unique to the GMT ASM allows low background observations at > 2 µm. For 25 m telescope, AO correction is needed even at 10 microns. Exoplanet imaging and planet formation science drivers are strengthened by this design choice. ASM and wide-field telescope design enables GLAO. Will increase the sensitivity and resolution of the planned multi-object NIR and visible spectrographs for GMT. Galaxy assembly and high-z science drivers are strengthened by this design choice.
20
GCAR, Pasadena CA, April 27-29, 2009 -- AO system20 System Performance System is designed to maximize science return with minimal technical development: Adaptive Secondary Mirrors are near-replicas of LBT, VLT design Laser Guide Star system builds on Na laser development for current telescopes. Laser Projection system is similar to MMT design. Expected AO performance is similar to MMT/LBT systems. Within the technical constraints above, the system performance and design is derived from the science requirements and the science instrument needs.
21
21 AO System Performance Wavefront error source RMS wavefront error (nm) NGSLTAOExAO Primary mirror figure20 15 Secondary mirror figure20 15 Piston anisoplanatism (1 min calibration)25 0 Piston errors from primary edge sensors25 AO optical train (non-common path)18210 Science instrument20 7 Fitting error121 80 Atmospheric temporal lag93 61 WFS measurement noise propagation832850 Reconstruction error52950 High order total189190117 Anisoplanatism error260 @13″148 @ 1'0 Residual windshake50 30 Total: On-axis196 121 Total: Off-axis325 @ 13″246 @ 1′
22
22 AO System Performance NGS performance versus guide star brightness 1 ms 2 ms 10 ms 5 ms AO System Performance versus wavelength S J = 36% S H = 56% S K = 72% S L’ = 90% S M = 94% Wavelength (µm) V magnitude (K5 star) K band Strehl Ratio Strehl Ratio
23
AO4ELT - Paris 200923
24
AO4ELT - Paris 200924 GMT 8.4m Off-Axis Prototype The first GMT primary segment is in the polishing/figuring stage Completion date: March 2010 GMT Segment #1 at the Steward Observatory Mirror Lab
25
AO4ELT - Paris 200925 Schedule
26
Astronomical Society of Australia Meeting - Perth July 0826 GMT’s AO Top-Level Requirements Play to its Strengths: Mid-IR with Adaptive Secondary Wide-field Ground-Layer AO Laser Tomography Seeing-Limited Requirements and Instruments are also important… High Dispersion Spectrographs Wide-field Multi-Object Spectrographs
27
Backup Slides
28
AO4ELT - Paris 200928 Adaptive Optics Prioritization GMT First Generation AO Modes: - “all sky” laser tomography AO high Strehl, 20 - 40 field of view, depending on - Ground layer adaptive optics 8 diameter field, factor of 2 - 4 improvement in FWHM, EE - Natural guide star AO high Strehl, small field of view, low thermal IR background Upgrade modes: MCAO (2nd DM in AO relay) ExAO (2nd DM in instrument)
29
AO4ELT - Paris 200929 L band detection limit 40x improved with ~3x larger diameter 3.8 um: 25 Jy10 um: 750 Jy 3 λ/D: 0.48”3 λ/D: 1.0” 3.8 um: 0.6 Jy10 um: 18 Jy 3 λ/D: 0.11”3 λ/D: 0.25” Detect 5-10 M J giant planets 100-300 zody warm debris disks Detect <1 M J planets 3-10 zody warm debris disks 1 hour 5 sigma limits Mid-IR Imaging of Exoplanets GMT can undertake comprehensive study of giant planets in > 3 AU range around stars at 30 pc.
30
AO4ELT - Paris 200930 AO Imaging of Young Planets 8m Angular Separation (mas) 2 /D at 1.5 m 42m30m25m8m
31
AO4ELT - Paris 200931 AO System Layout LGS Projector Laser beam relay Laser house Adaptive secondary mirror (ASM) AO Focal Plane Assembly (FPA) Optical relay LGS wavefront sensors Phasing camera AO instruments top view
32
AO4ELT - Paris 200932 AO System Overview Laser Housing Adaptive Secondary Mirror (~4700 actuators) Laser Projector AO relay and Narrow-field WFS GLAO WFS top view
33
AO4ELT - Paris 200933 Three independent measurements Principal optical test Full-aperture, interferometric test Scanning pentaprism test Measures low-order aberrations via slopes Laser Tracker Plus Scans surface with laser tracker Works on ground or polished surface
34
AO4ELT - Paris 200934 Phase Apodization 1.65 m, 5% band. Diffraction only, no wavefront error 10 -6 suppression at 4 /D, 56 mas 10 -5 companion
35
AO4ELT - Paris 200935 AO Imaging of Massive Planets Angular Separation (mas) 3 /D at 1 m 8m25m30m42m Log Contrast
36
AO4ELT - Paris 200936 AO Studies of Black Hole Demographics 8m GMT 1.22 /D @1.5 m
37
AO4ELT - Paris 200937 AO Imaging of Young Planets 8m Angular Separation (mas) 2 /D at 5 m GMT8m
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.