Next Generation Adaptive Optics (NGAO)Next Generation Adaptive Optics (NGAO)System Design Phase UpdateSystem Design Phase Update

Peter Wizinowich, Rich Dekany, Don Gavel, Claire MaxPeter Wizinowich, Rich Dekany, Don Gavel, Claire Max

Science Case Presenters: Brian Cameron, David Law, Jessica Lu, Science Case Presenters: Brian Cameron, David Law, Jessica Lu, Phil Marshall, Chuck Steidel, Tommaso TreuPhil Marshall, Chuck Steidel, Tommaso Treu

Technical Team: Sean Adkins, Brian Bauman, Jim Bell, Technical Team: Sean Adkins, Brian Bauman, Jim Bell, Antonin Bouchez, Matthew Britton, Jason Chin, Ralf Flicker, Antonin Bouchez, Matthew Britton, Jason Chin, Ralf Flicker,

Erik Johansson, David Le Mignant, Chris Lockwood, Liz McGrath, Erik Johansson, David Le Mignant, Chris Lockwood, Liz McGrath, Anna Moore, Chris Neyman, Viswa VelurAnna Moore, Chris Neyman, Viswa Velur

Keck Strategic Planning MeetingKeck Strategic Planning MeetingSeptember 20, 2007September 20, 2007

2

Presentation Sequence

1:00 pm WMKO Strategic Plan & NGAO (Wizinowich)

1:10 pm NGAO System Design Phase Status

1:15 pm Science Cases & Requirements– Overview (Max)– Precision astrometry at the Galactic Center & in sparse fields

(Cameron & Lu)– High redshift galaxies with multiple IFU’s (Steidel & Law)– Gravitationally lensed galaxies with single IFU’s (Marshall & Treu)

2:20 pm System Architecture (Dekany)

2:30 pm Discussion– Potential Topics

3:00 pm Done

WMKO Strategic Plan & NGAOWMKO Strategic Plan & NGAO

4

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!

5

Keck AO Strategic Plan: NGAO• AO strategic plan established by Keck AO Working Group

in Nov/02 & reaffirmed in Sept/04:

“AOWG 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

Substellar binaries

Refereed Keck AO Science Papers by Year & Type

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

2000 2001 2002 2003 2004 2005 2006 2007

Year

Nu

mb

er o

f Solar System

Galactic

Extra-galactic

126 NGS & 30 LGS

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Key new capabilities for NGAOKey new capabilities for NGAO1.1. Dramatically improved near-IR performanceDramatically 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

2.2. Increased sky coverage & MultiplexingIncreased sky coverage & Multiplexing• Improved tip/tilt correction Improved tip/tilt correction improved sky coverage improved sky coverage• Multiplexing Multiplexing dramatic efficiency improvements dramatic efficiency improvements Much broader range of science programsMuch broader range of science programs

3.3. AO correction at red wavelengthsAO correction at red wavelengths • Strehl of 15 - 25% at 750 nm highest angular resolution of any existing

filled aperture telescope

4.4. Instrumentation to facilitate the range of science programsInstrumentation to facilitate the range of science programs

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Key performance metrics: Key performance metrics: Strehl vs. observing wavelengthStrehl vs. observing wavelength

Current Current NGSNGS

CurreCurrent LGSnt LGS

NGAONGAO

H Ca Triplet

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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

NGAO System Design PhaseNGAO System Design PhaseStatusStatus

1111

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

# MILESTONE DATE STATUS

1 SD SEMP Approved 10/9/06 Complete

2 SD phase contracts in place 10/27/06 Complete

3 Science Requirements Summary v1.0 Release

10/27/06 Complete

4 System Requirements Document (SRD) v1.0 Release

12/8/06 Complete

5 Performance Budgets Summary v1.0 Release

6/15/07 Complete

6 SRD v2.0 Release 5/22/07 Nearly complete

7 Trade Studies Complete 6/22/07 Complete

8 SRD v3.0 Release

9/7/07 Not started

9 System Design Manual (SDM) v1.0 Release

9/21/07 Complete

10 Technical Risk Analysis V1.0 Release

9/21/07 Nearly complete

11 Cost Review Complete 12/7/07 Some work as part of system architecture

12 SDM v2.0 Release

2/12/08

13 System Design ReviewPackage Distributed

3/4/08

14 System Design Review 3/31/08

15 SDR Report & Project Planning Presentation at SSC meeting

4/14/08

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

Science Cases & Requirements Science Cases & Requirements

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OutlineOutline• What is complementary and scientifically unique What is complementary and scientifically unique

about Keck NGAO?about Keck NGAO?

– JWST, ALMA, TMTJWST, ALMA, TMT

– Other ground-based observatoriesOther ground-based observatories

• ““Science Cases” for NGAO: what are “science Science Cases” for NGAO: what are “science requirements” that will guide the design?requirements” that will guide the design?

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Key new capabilities for NGAOKey new capabilities for NGAO

1.1. Dramatically improved near-IR performanceDramatically improved near-IR performance

2.2. Increased sky coverage & MultiplexingIncreased sky coverage & Multiplexing

3.3. AO correction at red wavelengthsAO correction at red wavelengths

4.4. Instrumentation to facilitate the range of science programsInstrumentation to facilitate the range of science programs

17

Complementary to JWST, ALMAComplementary to JWST, ALMA

• JWST: 2013JWST: 2013– Much higher sensitivity longward of K band

NGAO emphasizing wavelengths > K band– JWST: “Expect same resolution as HST below 2 m”

NGAO has clear resolution advantage– No multi-object IFU capability

• ALMA: 2012ALMA: 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

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

18

Complementary to TMTComplementary 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 IFU’s– 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

• 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 Complementary with other ground-based observatoriesground-based observatories

• Other ground-based observatoriesOther ground-based observatories are largely focusing are largely focusing on wide fields with modest performance, or on very high on wide fields with modest performance, or on very high contrast AOcontrast AO

• ““Wide” field Wide” field (by AO standards):(by AO standards):

– Gemini South: Multi-conjugate AO – VLT: Ground layer AO

• High Contrast:High Contrast:– Gemini Planet Imager– VLT SPHERE

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Scale of new VLT AO projects is Scale of new VLT AO projects is reallyreally big big

• Hawk-I: 2012 with AOHawk-I: 2012 with AO– K-band imager, 7.5’ x 7.5’ field

• MUSE visible multi-IFU: 2012MUSE visible multi-IFU: 2012– 1' field, x 2 seeing improvement

• MUSE visible narrow field IFU: 2012MUSE 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

• 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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OutlineOutline• What is complementary and scientifically unique What is complementary and scientifically unique

about Keck NGAO?about Keck NGAO?

– JWST, ALMA, TMTJWST, ALMA, TMT

– Other ground-based observatoriesOther ground-based observatories

• ““Science Cases” for NGAO: what are “science Science Cases” for NGAO: what are “science requirements” that will guide the design?requirements” that will guide the design?

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Categorize science cases into 2 classesCategorize science cases into 2 classes

1.1. Key Science Drivers:Key Science Drivers:

– These push the limits of AO system, instrument, and telescope performance. Determine the most difficult performance requirements.

2.2. Science Drivers: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 DriversKey Science Drivers(in order of distance)(in order of distance)

1.1. Minor planets as remnants of early Solar SystemMinor planets as remnants of early Solar System

2.2. Planets around low-mass starsPlanets around low-mass stars

3.3. General Relativity at the Galactic CenterGeneral Relativity at the Galactic Center

4.4. Black hole masses in nearby AGNsBlack hole masses in nearby AGNs

5.5. High-redshift galaxiesHigh-redshift galaxies

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1.1. Minor planets as remnants of early Solar SystemMinor planets as remnants of early Solar System• I-band AO; high contrast; astrometry

2.2. Planets around low-mass starsPlanets around low-mass stars• High contrast at J, H bands

3.3. General Relativity at the Galactic CenterGeneral Relativity at the Galactic Center• Precision astrometry and radial velocities

4.4. Black hole masses in nearby AGNsBlack hole masses in nearby AGNs• Spatially resolved spectra at Ca triplet (8500 Å)

5.5. High-redshift galaxiesHigh-redshift galaxies• Multi-IFU spectroscopy; low backgrounds; high sky coverage

Key Science DriversKey Science Drivers(in order of distance)(in order of distance)

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Some Science Requirements from Some Science Requirements from Key Science Drivers (physical)Key Science Drivers (physical)

Wavelength 0.7 to 1.0 µm Galactic & Solar System science, nearby AGNs

0.9 to 2.45 µm All

Wavefront error ≤ 170 nm All Solar System, planets around low-mass stars, debris disks, nearby AGNs, QSO hosts, lensed galaxiesTip tilt error ≤ 15 mas over

≥ 30% of sky

≤ 3 mas Galactic Center

50% ensquared energy

within 70 mas over ≥ 30% of sky

High z galaxies, Galactic Center radial vel’s

IFU field of view ≤ 3" High-z field galaxies

Imaging field of view

≥10" Galactic Center

30" Reference field of view for design study

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Some Science Requirements from Some Science Requirements from Key Science Drivers (performance)Key Science Drivers (performance)

Background ≤ 30% over unattenuated sky+telescope background. Goal: ≤ 20%

High-redshift science

Astrometric precision 100 µas Galactic Center

500 µas Exo-planet primary mass

Sky coverage fraction ≥ 30% (areal average over all sky)

Extragalactic science, TNOs, ...

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Instrument Priorities from Key Science DriversInstrument Priorities from Key Science Drivers

1. Near-IR imager

2. Visible imager

3. Near-IR IFU (OSIRIS?)

4. Visible IFU

1. Deployable near-IR multi-object IFU

Narrow field: Multi-object:

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Some Science Cases have specific Some Science Cases have specific observing requirementsobserving requirements

• Efficient surveys: (e.g. asteroid companions and planets Efficient surveys: (e.g. asteroid companions and planets around low-mass stars)around low-mass stars)

• Optimizing overall science output of the ObservatoryOptimizing 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 Requirements from Science Drivers (short summary)Science Drivers (short summary)

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

Please send us your input!Please send us your input!Please send us your input!Please send us your input!

Near-IRRequirement Imager Spectrograph Imager Spectrograph Deployable IFU

l ( µm) 0.7-1.0 0.7-1.0 1.0-2.4 (+Y&z) 1.0-2.4 (+Y&z) 1.0-2.4 (+Y&z)Field of view diameter (") ≥ 3 ≥ 2 (goal ≥ 3) ≥ 15 for X4b ≥ 4 ≥ 1 x 3

Field of regard diameter (") na na na na ≥ 120Pixel size (mas) ≤ 7 (Nyquist at R) na ≤ 13 (Nyquist at J) na ≤ 35 (2 pixels/spaxel)

Minimum # of IFUs na na na na 4IFU separation na na na na > 1 IFU in 10x10"??

AO Background na na ≤ 30% of total ≤ 30% of total ≤ 30% of totalSky coverage ≥ 30% for X3 ≥ 30% for X3 ≥ 30% for X1,X3,X4b ≥ 30% for X3,X4a ≥ 30% for X2

High order WFE (nm) for ≤ 5" fov ≤ 170 ≤ 170 ≤ 170 ≤ 170 derivedTip/tilt error (mas) ≤ 15 ≤ 15 ≤ 15 for sky cover; ≤ 3 for G2 ≤ 15 derived

50% Ensquared energy (mas) na ≤ 25 na ≤ 25 ≤ 70

Companion sensitivity DI ≥ 7.5 at 0.75" for S1b na

DH ≥ 5.5 at 0.5" for S1b; DJ ≥ 8.5 at 0.1" & DJ ≥ 11 at

0.2" for G1 na naPhotometry (mag) g: ≤ 0.05 relative for na ≤ 0.05 relative for S1&G1 na na

Astrometry (mas) ≤ 1.5 relative for S1b na≤ 1.5-2 for S1b&G1; ≤ 0.1

for G2a na na

Visible Near-IR

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1.1. Asteroid size, shape, compositionAsteroid size, shape, composition

2.2. Giant Planets and their moonsGiant Planets and their moons

3.3. Debris disks and Young Stellar ObjectsDebris disks and Young Stellar Objects

4.4. Astrometry in sparse fieldsAstrometry in sparse fields

5.5. Resolved stellar populations in crowded fieldsResolved stellar populations in crowded fields

6.6. QSO host galaxiesQSO host galaxies

7.7. Gravitationally lensed galaxiesGravitationally lensed galaxies

Requirements based on these Science Drivers are still Requirements based on these Science Drivers are still under discussion - we need your input!under discussion - we need your input!

Requirements based on these Science Drivers are still Requirements based on these Science Drivers are still under discussion - we need your input!under discussion - we need your input!

Science DriversScience Drivers(in order of distance)(in order of distance)

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NGAO will allow us to tackle NGAO will allow us to tackle important, high-impact scienceimportant, high-impact science

1.1. Near diffraction-limited in near-IR (Strehl >80%)Near diffraction-limited in near-IR (Strehl >80%)• 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

2.2. Vastly increased sky coverage and multiplexingVastly increased sky coverage and multiplexing• Multi-object IFU surveys of distant galaxies

3.3. AO correction at red wavelengths (0.7-1.0 AO correction at red wavelengths (0.7-1.0 m)m)• 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 todayScience Case Presentations today

• Precision astrometry at Galactic Center & in sparse Precision astrometry at Galactic Center & in sparse fieldsfields– Brian Cameron and Jessica Lu

• Spectroscopy of high-redshift galaxiesSpectroscopy of high-redshift galaxies– Chuck Steidel and David Law

• Gravitationally lensed galaxiesGravitationally lensed galaxies– Tommaso Treu and Phil Marshall

Intended to illustrate NGAO science requirements development processIntended to illustrate NGAO science requirements development process

NGAO System Design: NGAO System Design: System Architecture System Architecture

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SystemArchitecture

Element Benefit

Eases packaging and cooling

Existing DM technology

Maximizes tip/tilt sky coverage

Reduces MOAO risk

Utilizes low-cost MEMS DM

Compact size requires small optics

MOAO-Corrected NIR Tip/Tilt Sensors

Maximizes sky coverage

Field-dependent PSF estimation

Routine system optimization

K-mirror Derotator Fixed gravity

Output instrument Switching Mirror Rapid instrument changes

Robustness to Cn2(h) variations

PSF Monitoring Capability

1st Relay(~200" FoV)

2nd Relay(30" FoV)

Variable-RadiusLGS Asterism

35

NGAO Fields of Regard5 LGS variableradius asterism

3 tip/tilt stars

202" LGS patrol range

180" FoR for tip-tilt star selection

Central LGS

RovingLGS

Multi-object deployable

IFU FoV

5 LGS on 11” radius

3 tip/tilt stars

1st Relay / DNIRIField of Regard

2nd Relay / Precision AO Field of Regard

120 arcsec 30 arcsec

36

System Design Progressing

Visible imager

Near-IR imager

Near-IR IFU (OSIRIS)

Telescope elevation bearing

Keck I or II right Nasmyth platform

LGS OSM

LGS wavefront sensors on

focus stages

Woofer DM

589 nm Light

f/45 narrow field AO relay

Narrow field selection mirror

IFU and tip-tilt OSM

2 channel IFU spectrograph (1 of 3)

Tip-tilt sensor (1 of 3)

K‑mirror image de-rotator

f/15 AO Relay

OMU Bench

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Conclusion: NGAO CapabilitiesConclusion: NGAO Capabilities1.1. Dramatically improved near-IR performanceDramatically 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

2.2. Increased sky coverage & MultiplexingIncreased sky coverage & Multiplexing• Improved tip/tilt correction Improved tip/tilt correction improved sky coverage improved sky coverage• Multiplexing Multiplexing dramatic efficiency improvements dramatic efficiency improvements Much broader range of science programsMuch broader range of science programs

3.3. AO correction at red wavelengthsAO correction at red wavelengths • Strehl of 15 - 25% at 750 nm highest angular resolution of any existing

filled aperture telescope

4.4. Instrumentation to facilitate the range of science programsInstrumentation to facilitate the range of science programs

Enables wide variety of new science within interests of Keck CommunityEnables wide variety of new science within interests of Keck Community