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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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Maxat ii

MAXAT-II

Woods Hole

17-18 September 1999


Overview

Overview

  • Science Drivers

  • Lessons of the past

  • Focusing on Science and Innovation


Global context

Chile

8 m

4 x 8m

Mauna Kea, Hawaii

Global context

8 m

10 m

10 m

8 m


Global context1

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


Hubble space telescope moved the goal posts

Space

Ground

Hubble Space Telescope moved the goal posts

Detected Telescope Diameter .

Signal Image Width 


Sensitivity gains for a 21 st century telescope

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 


Adaptive optics on 8m 10m telescopes globular cluster ngc6934

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


Challenging 8m 10m telescopes

OH line

Challenging 8m - 10m telescopes


Maxat ii

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


Scientific drivers for the next generation groundbased telescope

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)


What is the future of o ir groundbased astronomy

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

  • LBT100 100

  • Keck 1 & 2 + 165 157 + 11

  • VLTI + 200 201 + 20


What is the future of o ir groundbased astronomy1

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

  • LBT100 100

  • Keck 1 & 2 + 165 157 + 11

  • VLTI + 200 201 + 20

  • 20 m 20 316

  • 50-M Telescope 50 1950

  • OWL100 7147


The scientific impact modeled characteristics of 20m and 50m telescope

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)


The scientific impact relative gain of groundbased 20m and 50m telescopes compared to ngst

The Scientific Impact- Relative Gain of groundbased 20m and 50m telescopes compared to NGST

Imaging

Velocities ~30km/s

Groundbased

advantage

NGST advantage


The impact of technology

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


Quantifying innovation bypassing extrapolation

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


Changing the paradigm extrapolation is innovations worst enemy

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


Maxat ii

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


Innovation factors

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


Baseline approach ambitious at the outset

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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