Strategic Planning for Adaptive Optics at Keck

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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)

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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!
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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."

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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

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54 30 16
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Previous strategic plan
X

• Complete
• In progress
• Went to Gemini
• 77 Keck AO papers to date (!) including 5 laser
  guide star papers in the past 6 months

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K
Ha
J
H
X
X Keck NGS today
X
X
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Wider field MCAO (graph from Gemini S)

• Strehl and PSF approx. uniform over 1.5 arc
  min diameter field

MCAO
Conventional AO
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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

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Planetary Science KPAO is the most promising
technology
Jovian moons, asteroids, trans-neptunian objects
are small enough to fit into KPAOs field of
view KPAO in visible has high potential for
asteroids, TNOs

• Volcanism variable phenomenon
• Io
• Triton
• Enceladus

-gt find smaller fragments around asteroids and
TNOs (multiple systems) -gt Bulk-Density
and formation scenario
South pole clouds
Surface at 2 ?m
87 Sylvia and its two moonlets
Keck
Keck
Cryo-volcanoes?
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KPAO in visible has high potential for asteroids,
TNOs

• Better angular resolution, sensitivity(?),
  spectral capabilities
• PSF quality and stability sensitivity must be
  quantified

• Better angular resolution
• Better sensitivity?
• -gt find smaller fragments around asteroids and
  TNOs (multiple systems)
• -gt Bulk-Density and formation scenario

87 Sylvia and its two moonlets(Marchis et al.
2005)
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What is the diversity of planetary
systems?Imaging of dusty circumstellar disks
KPAO can fulfill needs of most Galactic Astronomy
programs

• 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 _at_ I-band resolution 0.01
  (0.1-0.5 AU scales).

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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 _at_ 50 AU
• These targets are inaccessible to bright-star
  ExAO systems

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KPAO better orbits for stars around Galactic Ctr
? General Relativity
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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

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NGS AO
MCAO AO
LGS AO
(1)
(2)
(3)
GOODS-N
GOODS-N
GOODS-N
1
15
35
MOAO AO
Metallicity Gradients
(4)
Velocity Kinematics
Star Formation Rates
(5)
0.5
(6)
-
Note Sauron Data from local galaxies, de Zeeuw
et al. 2002
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Synergy between KPAO and wide field AO options
KPAO will measure turbulence using multiple laser
guide stars and tomography
KPAO narrow FOV High Strehl
Wide field AO will use these measts to correct
atmosphere
Multi-Object AO Many small fields of view within
larger field of regard, moderate Strehl
Multi-Conjugate AO 2 FOV Moderate Strehl
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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

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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!)

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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 doesnt (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