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

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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

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Wavelength (nm)

Strehl

110 nm120 nm130 nm

J H KH

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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?

KPAO: better orbits for stars around Galactic Ctr General Relativity

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

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StarFormation

Rates

1% 15%

35%

Note: Sauron Data from local galaxies, de Zeeuw et al. 2002

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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