Next Generation Adaptive Optics NGAO System Design Phase Update

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Next Generation Adaptive Optics (NGAO)System
Design Phase Update

• Peter Wizinowich, Rich Dekany, Don Gavel, Claire
  Max
• Science Case Presenters Brian Cameron, David
  Law, Jessica Lu,
• Phil Marshall, Chuck Steidel, Tommaso Treu
• Technical Team Sean Adkins, Brian Bauman, Jim
  Bell,
• Antonin Bouchez, Matthew Britton, Jason Chin,
  Ralf Flicker,
• Erik Johansson, David Le Mignant, Chris Lockwood,
  Liz McGrath, Anna Moore, Chris Neyman, Viswa
  Velur
• Keck Strategic Planning Meeting
• September 20, 2007

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Presentation Sequence

• 100 pm WMKO Strategic Plan NGAO (Wizinowich)
• 110 pm NGAO System Design Phase Status
• 115 pm Science Cases Requirements
• Overview (Max)
• Precision astrometry at the Galactic Center in
  sparse fields (Cameron Lu)
• High redshift galaxies with multiple IFUs
  (Steidel Law)
• Gravitationally lensed galaxies with single IFUs
  (Marshall Treu)
• 220 pm System Architecture (Dekany)
• 230 pm Discussion
• Potential Topics
• 300 pm Done

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WMKO Strategic Plan NGAO
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Keck Strategic Plan Twenty-year strategic goals

• Leadership in high angular resolution astronomy
• Leadership in state of the art instrumentation
• Highly efficient observing
• Complementarity with ELTs
• NGAO supports all of these!

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Keck AO Strategic Plan NGAO

• AO strategic plan established by Keck AO Working
  Group in Nov/02 reaffirmed in Sept/04AOWG
  vision is that high Strehl, single-object, AO
  will be the most important competitive point for
  Keck AO in the next decade.
• Sept/05 New AOWG tasked by Observatory SSC to
  develop science case for Keck NGAO.
• Jun/06. NGAO proposal approved.
• Multi-object also emphasized

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Keck AO Science Productivity
126 NGS 30 LGS
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Key new capabilities for NGAO

• Dramatically improved near-IR performance
• Significantly higher Strehls (? 80 at K) ?
  improved sensitivity
• Lower backgrounds ? improved sensitivity
• Improved PSF stability knowledge ? improved
  photometry, astrometry companion sensitivity
• Increased sky coverage Multiplexing
• Improved tip/tilt correction ? improved sky
  coverage
• Multiplexing ? dramatic efficiency improvements
• ? Much broader range of science programs
• AO correction at red wavelengths
• Strehl of 15 - 25 at 750 nm ? highest angular
  resolution of any existing filled aperture
  telescope
• Instrumentation to facilitate the range of
  science programs

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Key performance metrics Strehl vs. observing
wavelength
Ca Triplet
H?
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System Architecture

• Tomography to measure wavefronts overcome cone
  effect
• AO-corrected, IR tip-tilt stars for broad sky
  coverage
• Closed-loop AO for 1st relay
• Open-loop AO for deployable IFUs 2nd relay

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NGAO System Design PhaseStatus
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NGAO System Design Phase

• System Design Phase. Oct/07 to Apr/08.
• Executive Committee established to manage this
  phase
• Wizinowich (WMKO, chair), Dekany (Caltech), Gavel
  (UCSC), Max (UCSC, project scientist)
• Deliverables
• Science Observatory requirements flow down to
  system requirements
• Performance budgets, functional requirements,
  system subsystem architectures
• Management plan for remaining NGAO phases

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System Design Milestones
Requirements ? Performance Budgets Trade
Studies ? System Architecture Functional
Requirements ? Subsystem Design Functional
Requirements ? Management Plan
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System Design Products

• All products maintained at NGAO TWiki site
• (just Google NGAO)
• including
• Requirements documents (Science case, System
  Functional)
• Performance budget reports (wavefront error
  encircled energy, astrometry, photometry,
  companion sensitivity throughput/emissivity)
• Model assumption validation reports (total of
  14)
• Trade study reports (total of 23)
• Management plans reports
• Goal of NGAO shared-risk science in 2013

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Science Cases Requirements
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Outline

• What is complementary and scientifically unique
  about Keck NGAO?
• JWST, ALMA, TMT
• Other ground-based observatories
• Science Cases for NGAO what are science
  requirements that will guide the design?

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Key new capabilities for NGAO

• Dramatically improved near-IR performance
• Increased sky coverage Multiplexing
• AO correction at red wavelengths
• Instrumentation to facilitate the range of
  science programs

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Complementary to JWST, ALMA

• JWST 2013
• Much higher sensitivity longward of K band
• NGAO emphasizing wavelengths gt K band
• JWST Expect same resolution as HST below 2 ?m
• NGAO has clear resolution advantage
• No multi-object IFU capability
• ALMA 2012
• Spatial resolution as low as 0.01 to 0.1 arc sec
  (!)
• Complementary data on dust cold gas

Our goal is to position NGAO to build on, and
complement, JWST ALMA discoveries
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Complementary to TMT

• TMT IRMS AO multi-slit, based on MOSFIRE
• Slits 0.12 and 0.16, Field of regard 2 arc
  min
• Lower backgrounds 10 of sky telescope
• NGAO with multiplexed deployable IFUs
• Multi-object AO ? better spatial resolution
  (0.07) over full field
• Backgrounds ? 30 of sky telescope

• Pros for TMT lower backgrounds, higher
  sensitivity
• Pros for NGAO higher spatial resolution, 2D
  information, better wide field performance

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Complementary with other ground-based
observatories

• Other ground-based observatories are largely
  focusing on wide fields with modest performance,
  or on very high contrast AO
• Wide field (by AO standards)
• Gemini South Multi-conjugate AO
• VLT Ground layer AO
• High Contrast
• Gemini Planet Imager
• VLT SPHERE

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Scale of new VLT AO projects is really big

• Hawk-I 2012 with AO
• K-band imager, 7.5 x 7.5 field
• MUSE visible multi-IFU 2012
• 1' field, x 2 seeing improvement
• MUSE visible narrow field IFU 2012
• 7.5 field, 5 Strehl at 750 nm

• NGAO must strike balance between scale/cost,
  risk, and science return.
• Lesson from these VLT projects have courage, but
  be realistic too

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Outline

• What is complementary and scientifically unique
  about Keck NGAO?
• JWST, ALMA, TMT
• Other ground-based observatories
• Science Cases for NGAO what are science
  requirements that will guide the design?

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Categorize science cases into 2 classes

• Key Science Drivers
• These push the limits of AO system, instrument,
  and telescope performance. Determine the most
  difficult performance requirements.
• Science Drivers
• These are less technically demanding but still
  place important requirements on available
  observing modes, instruments, and PSF knowledge.

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Key Science Drivers(in order of distance)

• Minor planets as remnants of early Solar System
• Planets around low-mass stars
• General Relativity at the Galactic Center
• Black hole masses in nearby AGNs
• High-redshift galaxies

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Key Science Drivers(in order of distance)

• Minor planets as remnants of early Solar System
• I-band AO high contrast astrometry
• Planets around low-mass stars
• High contrast at J, H bands
• General Relativity at the Galactic Center
• Precision astrometry and radial velocities
• Black hole masses in nearby AGNs
• Spatially resolved spectra at Ca triplet (8500 Å)
• High-redshift galaxies
• Multi-IFU spectroscopy low backgrounds high sky
  coverage

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Some Science Requirements from Key Science
Drivers (physical)
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Some Science Requirements from Key Science
Drivers (performance)
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Instrument Priorities from Key Science Drivers
Narrow field
Multi-object

• Deployable near-IR multi-object IFU

• Near-IR imager
• Visible imager
• Near-IR IFU (OSIRIS?)
• Visible IFU

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Some Science Cases have specific observing
requirements

• Efficient surveys (e.g. asteroid companions and
  planets around low-mass stars)
• Optimizing overall science output of the
  Observatory
• Seeing and AO correction are variable
• Requirements on ability to switch to NGS, and to
  other instruments
• What kinds of flexible observing might be
  appropriate?

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Science Requirements from Science Drivers (short
summary)

• An eye test here, but printed out on your
  handout sheets.

Please send us your input!
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Science Drivers(in order of distance)

• Asteroid size, shape, composition
• Giant Planets and their moons
• Debris disks and Young Stellar Objects
• Astrometry in sparse fields
• Resolved stellar populations in crowded fields
• QSO host galaxies
• Gravitationally lensed galaxies

Requirements based on these Science Drivers are
still under discussion - we need your input!
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NGAO will allow us to tackle important,
high-impact science

• Near diffraction-limited in near-IR (Strehl gt80)
• Direct detection of planets around low-mass stars
• Astrometric tests of general relativity in the
  Galactic Center
• Structure kinematics of subcomponents in high
  redshift galaxies
• Vastly increased sky coverage and multiplexing
• Multi-object IFU surveys of distant galaxies
• AO correction at red wavelengths (0.7-1.0 mm)
• Scattered-light studies of debris disks and their
  planets
• Masses and composition of asteroids and Kuiper
  Belt objects
• Mass determinations for supermassive black holes

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Science Case Presentations today

• Precision astrometry at Galactic Center in
  sparse fields
• Brian Cameron and Jessica Lu
• Spectroscopy of high-redshift galaxies
• Chuck Steidel and David Law
• Gravitationally lensed galaxies
• Tommaso Treu and Phil Marshall

Intended to illustrate NGAO science requirements
development process
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NGAO System Design System Architecture
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SystemArchitecture
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NGAO Fields of Regard
5 LGS variable radius asterism
180" FoR for tip-tilt star selection
202" LGS patrol range
3 tip/tilt stars
3 tip/tilt stars
5 LGS on 11 radius
Roving LGS
Central LGS
Multi-object deployable IFU FoV
30 arcsec
120 arcsec
1st Relay / DNIRIField of Regard
2nd Relay / Precision AO Field of Regard
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System Design Progressing
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Conclusion NGAO Capabilities

• Dramatically improved near-IR performance
• Significantly higher Strehls (? 80 at K) ?
  improved sensitivity
• Lower backgrounds ? improved sensitivity
• Improved PSF stability knowledge ? improved
  photometry, astrometry companion sensitivity
• Increased sky coverage Multiplexing
• Improved tip/tilt correction ? improved sky
  coverage
• Multiplexing ? dramatic efficiency improvements
• ? Much broader range of science programs
• AO correction at red wavelengths
• Strehl of 15 - 25 at 750 nm ? highest angular
  resolution of any existing filled aperture
  telescope
• Instrumentation to facilitate the range of
  science programs

Enables wide variety of new science within
interests of Keck Community