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MAXAT-II

MAXAT-II. Woods Hole 17-18 September 1999. Overview. Science Drivers Lessons of the past Focusing on Science and Innovation. Chile. 8 m. 4 x 8m. Mauna Kea, Hawaii. Global context. 8 m. 10 m. 10 m. 8 m. OWL. CELT. MAXAT. Phase A. 2008. 2000. 2010. 2015. Global context.

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MAXAT-II

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  1. MAXAT-II Woods Hole 17-18 September 1999

  2. Overview • Science Drivers • Lessons of the past • Focusing on Science and Innovation

  3. Chile 8 m 4 x 8m Mauna Kea, Hawaii Global context 8 m 10 m 10 m 8 m

  4. OWL CELT MAXAT Phase A 2008 2000 2010 2015 Global context 2000 2010 Keck I&II Keck-Inter. ESO-VLTI NGST ALMA VLA-upgrade UT1,UT2,UT3,UT4 Gemini N&S HET LBT

  5. Space Ground Hubble Space Telescope moved the goal posts Detected Telescope Diameter . Signal Image Width 

  6. OH line OH line Sensitivity gains for a 21st Century telescope For background or sky noise limited observations: S(Effective Collecting Area)1/2 . N Delivered Image Diameter  S/N x (106)1/2 Detected Telescope Diameter . Signal Image Width 

  7. V-band 0.6 arcsec 2.2um (K) Hokupa’a ON Adaptive Optics on 8m -10m Telescopes Globular Cluster NGC6934 • V (0.55um) band • FWHM of 0.6” • K (2.2um) band • ~120 exposures totaling 23min • FWHM of 0.09” Gemini Optical Image

  8. OH line Challenging 8m - 10m telescopes

  9. Observations at z = 2 - 5 1 - 10 milli- arcseconds Velocity dispersion R= 105 104 103 102 101 Imaging Spectroscopy  10 AU Galactic observations out to 1kpc at 10 mas resolution Going beyond 0.1 arcsecond astronomy requires resolution and sensitivity Flux 1 AU 1 R 100 AU 10 pc 100 pc 0.1 pc Accretion Disks Molecular Cloud Cores Mol. Outflows GMC Protoplanetary Disks AGN Jets/HH Planets Stellar Clusters

  10. Scientific Drivers for the “Next Generation Groundbased Telescope” • MaximizeTelescope Diameter .Image Diameter • For diffraction limitedpixels S/N a D2 /l • In the detector limited regimeS/N a D2 Detector technology (t)

  11. What is the future of O/IR Groundbased Astronomy? Facility Baseline (m) Collecting Area (m2) • Gemini 8-M 8 2 x 50 • HET 9 60 • CHARA 354 5.5 • LBT 100 100 • Keck 1 & 2 + 165 157 + 11 • VLTI + 200 201 + 20

  12. What is the future of O/IR Groundbased Astronomy? - technology enables innovation and, scientific discovery Facility Baseline (m) Collecting Area (m2) • Gemini 8-M 8 2 x 50 • HET 9 60 • CHARA 354 5.5 • LBT 100 100 • Keck 1 & 2 + 165 157 + 11 • VLTI + 200 201 + 20 • 20 m 20 316 • 50-M Telescope 50 1950 • OWL 100 7147

  13. The Scientific Impact- Modeled characteristics of 20m and 50m telescope Assumed point source size (mas) 20M 1.2mm 1.6mm 2.2mm 3.8mm 4.9mm 12mm 20mm (mas) 20 20 26 41 58 142 240 50M 1.2mm 1.6mm 2.2mm 3.8mm 4.9mm 12mm 20mm (mas) 10 10 10 17 23 57 94 h 70% 70% 50% 50% 50% 50% 50% Assumed detector characteristics 1mm < l < 5.5mm 5.5mm < l < 25mm Id Nr qe Id Nr qe 0.02 e/s 4e 80% 10 e/s 30e 40% (Gillett & Mountain, 1998)

  14. The Scientific Impact- Relative Gain of groundbased 20m and 50m telescopes compared to NGST Imaging Velocities ~30km/s Groundbased advantage NGST advantage

  15. x 10 -100 Mass = 340 tonnes Cost (1998) ~ $64M scaled to 8m ~ $415M Mass = 315 tonnes Cost (1998) ~ $88M The impact of technology Kitt Peak 4m c.1970 Gemini 8m c.1998

  16. Quantifying Innovation- bypassing extrapolation 4m (KPNO) 8m (Gemini) Cost(1998) $61M Scaled cost $415M Actual cost $88M Cost “gain” x ~5 Image quality 1” Image quality 0.1” Performance “gain” (rel. to diff.) x 5 “innovation factor” ~ 5 x 5 = 25

  17. Changing the “paradigm”- “extrapolation is innovations worst enemy” NASA • Why ? • Because the science drives us to this scale • and because modern analytical and control systems techniques allows us to reduce risk HST NGST

  18. GEMINI IMAGE - 8 weeks into commissioning Tip/tilt sampling = 100Hz Open loop Arcsecondsjitter Pointing accuracy with active control of structure Feb ‘99 End-to-End modeling worksGemini Systems Review #2, March 1995 • Telescope error budget, 50% e-e diameter (arcsecs) at 2.2mm • System at 45 degrees, wind at 11 m/s, 200Hz tip/tilt sampling • Error budget allocation is 0.100 at Zenith, 0.0123 at 45 degrees

  19. HST NGST’ ($2.4B) ($1B) Keck + LGS AOCELT ($100M) ($400M) VLTOWL ($100M) ($1B) Gemini + MCAO50m ($100M) ($1B) Innovation Factors Innovation factor 27 - 70 80 5 12 50m $600M 20

  20. Baseline Approach - ambitious at the outset • Diffraction limited telescope D ~ 50m - 100m • Operating wavelengths Tech. challenge 0.9mm - 3.8mm Science challenge • Operate over 90% of sky (airmass < 2.0) • at full image quality over 75% • Operate under 90% of site conditions • at full performance under 75% of conditions • 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

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