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Strategic Planning for Adaptive Optics at Keck
Claire Max and Mike Liu
on behalf of Keck AO Working Group
Antonin Bouchez (Caltech), Rich Dekany (Caltech), David Koo (UCSC), Bruce
Macintosh (LLNL), Franck Marchis (UCB), Keith Matthews (Caltech)
Outline
• Role of AO Working Group
• Near-term Keck AO
• Strategic planning:– Previous strategic plans
– What should next-generation AO system look like:
– High Strehl over narrow field?
– Moderate Strehl over wider field?
– Other?
We need your feedback!
We need your help to compare science cases for future AO options!
We need your feedback!
We need your help to compare science cases for future AO options!
AO Working Group
• Second-generation AO Working Group
• Co-chairs: Mike Liu (UH) and Claire Max (UCSC)
• Members: Antonin Bouchez (Caltech), Rich Dekany (Caltech), David Koo (UCSC), Bruce Macintosh (LLNL), Franck Marchis (UCB), Keith Matthews (Caltech)
• Charter: "To assist in prioritization and advocate the optimization of the scientific output of the Keck adaptive optics facilities, in conjunction with the adaptive optics science instruments."
Near-term Keck AO
• Current Status:– Keck II laser guide star now doing shared-risk
science– Working VERY well (5 science papers from past
semester, many more coming)
• Near-term upgrades:– Wavefront controller upgrade (KI and KII)– Procurement of laser for KI under way
• 77 Keck AO papers to date (!) including 5 laser guide star papers in the past 6 months
2000 2001 2002 2003 20042005N
2005L
ExtraGal
Planetary
Galactic0
2
4
6
8
10
12
Keck AO Refereed Science Papers 77 (including 5 Interferometer).
54%30%16%
5 LGS
Previous strategic plan
Complete In progress
X Went to Gemini
• 77 Keck AO papers to date (!) including 5 laser guide star papers in the past 6 months
X
We need your advice
KPAO Strehl in visible and near-infrared
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
300 800 1300 1800 2300
Wavelength (nm)
Strehl
110 nm120 nm130 nm
J H KH
X
X
X
X Keck
NGS today
Wider field MCAO (graph from Gemini S)
•Strehl and PSF approx. uniform over ~ 1.5 arc min diameter field
MCAO
Conventional AO
Should we continue to pursue KPAO, or should we head to wider field AO? • Comparison of KPAO with Gemini MCAO
K band J band 8000A H
KPAO Strehl 90% 65% 40% 22% MCAO Strehl 60% 20% 2% very low
MCAO advantage
KPAO advantage
Planetary Science: KPAO is the most promising technology
Jovian moons, asteroids, trans-neptunian objects are small enough to fit into KPAO’s field of view
KPAO in visible has high potential for asteroids, TNO’s
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Volcanism: variable phenomenon• Io• Triton• Enceladus
South pole clouds Surface at 2 m
Keck
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Keck
Cryo-volcanoes?
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-> find smaller fragments around asteroids and TNO’s (multiple systems)
-> Bulk-Density and formation scenario
87 Sylvia and its two moonlets
KPAO in visible has high potential for asteroids, TNO’s
• Better angular resolution, sensitivity(?), spectral capabilities• PSF quality and stability + sensitivity must be quantified
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• Better angular resolution
• Better sensitivity?
-> find smaller fragments around asteroids and TNO’s (multiple systems)
-> Bulk-Density and formation scenario
87 Sylvia and its two moonlets(Marchis et al. 2005)
What is the diversity of planetary systems?Imaging of dusty circumstellar disks
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• Disk sub-structure tells about the planet formation process.
• Low-mass planets too faint to directly image can be studied by the dynamical signatures they produce in the dust.
• Multi-wavelength optical + IR colors tell us about grain growth.
• KPAO AO @ I-band: resolution ~0.01” (0.1-0.5 AU scales).
KPAO can fulfill needs of most Galactic Astronomy programs
KPAO: Imaging of planets around low-mass stars and brown dwarfs
• KPAO can detect 1 MJ companion to 40 MJ/10 Gyr brown dwarf
• Can detect 1 MJ companion to T Tauri star @ 50 AU
• These targets are inaccessible to bright-star ExAO systems
System Detectable contrast @ 0.5”
Mag. Limit
Current AO 104-105 R<18 mag
Extreme AO 107-108 I<9 mag
KPAO 105-106 H<18 mag?
Extragalactic astronomy requires large samples: some preference for wide field of view AO
• Color-magnitude diagrams of stars out to Virgo– Best with KPAO (higher Strehl for confusion limited
imaging)
• Wide field AO preferred for– Evolution of bulges, disks, bars, AGNs, starbursts at
high z– Multi-IFU spectroscopy and high resolution imaging
are possible (in principle) with both MCAO and MOAO
• We will understand galaxy evolution by using large samples of galaxies at high z
• Tradeoff between sensitivity (Strehl) and sample size
GOODS-N GOODS-NGOODS-N
NGS AO MCAO AOLGS AO
MOAO AO
z=1 Galaxy
Bulge
Spiral Arm
Super Nova?
HII region
VelocityKinematics
MetallicityGradients
-
StarFormation
Rates
1% 15%
35%
Note: Sauron Data from local galaxies, de Zeeuw et al. 2002
(1) (2) (3)
(6)
(5)
(4)
0.5”
KPAO narrow FOV High Strehl
Multi-Conjugate AO2’ FOVModerate Strehl
Multi-Object AOMany small fields of view within larger field of regard, moderate Strehl
Synergy between KPAO and wide field AO options
KPAO will measure turbulence using multiple laser guide stars and tomography
Wide field AO will use these meas’ts to correct atmosphere
Key Issue: Need to compare the science cases for KPAO, wide field AO• AOWG has put
together a few example science cases
• Gemini MCAO Science Case is much more extensive
• We need your help in fleshing out a science-case comparison between KPAO and wide-field AO
External environment considerations• HST is possibly/probably going to die in 3-5 years
– After that, Keck AO would be the best/only high resolution system available.
• In the optical, Keck could deliver 4x the resolution as HST – For high-resolution science in local universe (e.g.resolved stellar
population studies of nearby galaxies), 64x the effective volume would be available, so a much larger sample of objects can be studied.
• Laser technology is making significant strides– Lasers for Gemini MCAO are being built today– Lasers for optical AO are no longer a pipe dream
• TMT is a long way in the future– There is ample time for at least one next-generation Keck AO
system (and likely more).
• For planetary science, next-generation Keck AO will happen a lot sooner than any new space missions (except Moon-Mars!)
We need your input!
• What capabilities would you need from a next-generation Keck AO system for your own science?
– NOW is the time to begin planning this– Are you most excited about a high Strehl, modest FOV
AO system with optical (red) wavelength capability?– Would a larger field of view with lower Strehl but only IR
wavelength coverage be of most interest to you?
• HST users: what does HST provide for you that Keck AO doesn’t (aside from funding)?
• Please help us work on comparing science cases!– Form a mini-working group– CfAO and Keck could co-sponsor a workshop– Science closely tied with AO and instrument capabilities