Strategic Planning for Adaptive Optics at Keck

Claire Max and Mike Liuon 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!

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 2004 2005N 2005L

ExtraGal

Planetary

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Keck AO Refereed Science Papers 77 (including 5 Interferometer).

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5 LGS

Previous strategic plan

Complete In progressX 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

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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 technologyJovian moons, asteroids, trans-neptunian objects

are small enough to fit into KPAO’s field of viewKPAO 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 magExtreme AO 107-108 I<9 magKPAO 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 AOz=1 Galaxy

Bulge

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Super Nova?

HII region

VelocityKinematics

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StarFormation

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

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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