W. M. Keck Observatory’s Next Generation Adaptive Optics (NGAO) Facility Peter Wizinowich, Sean Adkins, Rich Dekany, Don Gavel, Claire Max for NGAO Team:

W. M. Keck Observatory’sW. M. Keck Observatory’sNext Generation Adaptive OpticsNext Generation Adaptive Optics

(NGAO) Facility(NGAO) FacilityPeter Wizinowich, Sean Adkins, Rich Dekany, Peter Wizinowich, Sean Adkins, Rich Dekany,

Don Gavel, Claire MaxDon Gavel, Claire Maxfor NGAO Team:for NGAO Team: R. Bartos, J. Chin, A. Conrad, A. Delacroix, R. Kupke, R. Bartos, J. Chin, A. Conrad, A. Delacroix, R. Kupke, C. Lockwood, J. Lyke, E. McGrath, D. Medeiros, D. Morrison, C. Neyman, C. Lockwood, J. Lyke, E. McGrath, D. Medeiros, D. Morrison, C. Neyman,

S. Panteleev, C. Pollard, M. Reinig, T. Stalcup, S. Thomas, M. Troy, S. Panteleev, C. Pollard, M. Reinig, T. Stalcup, S. Thomas, M. Troy, K. Tsubota, V. Velur, K. Wallace, E. WetherellK. Tsubota, V. Velur, K. Wallace, E. Wetherell

SPIE, San DiegoSPIE, San DiegoJune 28, 2010June 28, 2010

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Context for NGAO – growing demand for LGS-AO on large telescopes

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Credit: M. Liu

Refereed Keck AO Science Papers by Year

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45

50

1999 2001 2003 2005 2007 2009

Year

Nu

mb

er o

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aper

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~270 Keck AO science papers

~50% of Keck II science nights

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NGAO - Next Generation AO

Key New Science Capabilities

Near Diffraction-Limited in Near-IR (K-Strehl ~80%)

AO correction at Red Wavelengths (0.7-1.0 m)

Increased Sky Coverage

Improved Angular Resolution, Sensitivity and Contrast

Improved Photometric and Astrometric Accuracy

Imaging and Integral Field Spectroscopy

Key Science Goals

Understanding the Formation and Evolution of Today’s Galaxies since z=3

Measuring Dark Matter in our Galaxy and Beyond

Testing the Theory of General Relativity in the Galactic Center

Understanding the Formation of Planetary Systems around Nearby Stars

Exploring the Origins of Our Solar System

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Flowed-Down Key Architectural FeaturesG

alax

y A

ssem

bly

BH

mas

ses

in

near

by

AG

Ns

GR

at

the

Gal

actic

Cen

ter

Pla

nets

aro

und

low

-mas

s st

ars

Min

or P

lane

ts

Lase

r to

mog

raph

y

AO

-cor

rect

ed

NIR

TT

Coo

led

AO

Hig

h-o

rder

DM

DA

VIN

CI

Near diffraction-limited in near-IR

AO correction at red wavelengths

Increased sky coverage

Improved sensitivity

Improved contrastImproved photometric

accuracyImproved astrometric

accuracy

ImagingIntegral field spectroscopy

Key Science Drivers Key Architectural Features

Key New Science Capabilities

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NGAO System Architecture

Key Features:1. Fixed narrow field laser tomography2. AO corrected NIR TT sensors3. Cooled AO enclosure4. Cascaded relay5. Combined imager/IFU instrument

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NGAO: AO Layout

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NGAO: AO Bench

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LGS Wavefront Sensor Assembly

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Low Order Wavefront Sensor Assembly

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DAVINCI – Imager & IFS

Entrance window

Coronagraph mask wheel

Imager detector

headImager/IFS

selector mirror

Pupil imager wheel

Filter and pupil mask wheels

IFS detector head

Grating selector wheel

• On axis imager 28.7" x 28.7" FOV– 7 mas pixel scale

• On axis selectable IFS– 50 mas pixel scale FOV 5.6" x 3"

– 35 mas, FOV 3.92" x 2.1"

– 10 mas, FOV 1.12" x 0.6"

Adkins et al.7735-287

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AO Enclosure

DAVINCI Instrument

Overhead HEPAs

LGSWFS

Gowning Room Area

AO Bench

Secondary Instrument

Interferometer DSM

Thermal Management

DM Electronics

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LGS Facility

TOPTICA/MPBC7736-252

RC Optical

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Control Loops – LGS AO Example

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Control Loops – LGS AO Example

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Control Loops – LGS AO Example

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Control Loops – LGS AO Example

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Control Loops – LGS AO Example

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Control Loops – LGS AO Example

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The RTC System Architecture is Mapped to the Critical Signal Paths

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At the heart of the science wavefront control is the Tomography Engine

TomographyTomography

Tip/TiltTip/Tilt

TT Star Sharpenning

TT Star Sharpenning

Reinig & Gavel7736-130

2020

Science Case Performance Summary

10 mas

35 mas

50 mas

70 mas

1Galaxy Assembly K 158 4.9 180 77% 4% 36% 56% 75%

2 Nearby AGN Z 158 4.8 176 21% 8% 29% 30% 31%

3aGalactic Center Imaging K 208 2.2 212 69% 4% 31% 48% 65%

3bGalactic Center Spectra H 191 2.4 195 57% 5% 38% 52% 59%

4 Exo-planets H 155 2.9 162 68% 6% 46% 62% 71%5 Minor Planets Z 157 4.7 175 21% 8% 29% 30% 31%6 Io Z 116 2.1 119 48% 14% 51% 53% 53%

Ensquared Energy in Spaxel

Case # Science Case

Science Band

RMS High-order

Wavefront Error (nm)

RMS Tip-Tilt Error

(mas)

Effective RMS

Wavefront Error (nm)

Strehl Ratio

Galaxy assembly: 30º zenith angle, 60º galactic latitude, 30 min integ.

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NGAO Performance vs. Sky Coverage NGAO Performance vs. Sky Coverage (Galaxy Assembly Science Case)(Galaxy Assembly Science Case)

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Strehl

EE 35 mas

EE 50 mas

EE 70 mas

Resid. TT error

• Nominal Ensquared Energy (EE) requirement = 30% sky coverage

• But very little degradation in EE even for 70% sky coverage

• Nominal Ensquared Energy (EE) requirement = 30% sky coverage

• But very little degradation in EE even for 70% sky coverage

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NGAO is robust against conditions and design

assumptions

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0%10%20%30%40%50%60%70%80%90%

100%

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Fram

e ra

te [H

z]

K-ba

nd S

treh

l rati

o or

Ens

quar

ed E

nerg

y

r0 [m]

Strehl EE 35 mas EE 50 mas EE 70 mas HO WFS Frame Rate

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0%10%20%30%40%50%60%70%80%90%

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Fram

e ra

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z]

K-ba

nd S

treh

l rati

o or

Ens

quar

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nerg

y

Total Fixed Laser Asterism Power [W]

Strehl EE 35 mas EE 50 mas EE 70 mas HO WFS Frame Rate

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0%10%20%30%40%50%60%70%80%90%

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Fram

e ra

te [H

z]

K-ba

nd S

treh

l rati

o or

Ens

quar

ed E

nerg

y

Zenith Angle [deg]

Strehl EE 35 mas EE 50 mas EE 70 mas HO WFS Frame Rate

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5% 10%

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30%

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Freq

uenc

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K-band Strehl Ratio

AO performance comparison

Liu's K2 LGS AO Data K2 LGS AO Model NGAO Model

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NGAO changes the AO observing experience

Monte Carlo performance estimate simulating 44 nights observing (Galaxy Assembly science case), drawing random values for r0, wind speed, sodium

abundance, and zenith angle

Includes comparison with M. Liu’s measured K2 LGS data (<SR> = 17%), the model prediction for K2 LGS (<SR> = 20%), and NGAO predict (<SR> = 70%)

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Early Science Benefits from NGAO - 1

• NGAO laser launch telescope– NSF-MRI (Aug/09) funding to procure & implement a K2 center

launch telescope

• NGAO laser– Preliminary designs completed (Dec/09) from 2 vendors.

Collaboration with ESO, AURA, GMT & TMT. TOPTICA/MPBC selected to begin final design.

– MRI proposal submitted to procure & implement 1st NGAO laser on K2. Collaboration with TMT & ESO

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Relative Positional Error

0.00

0.50

1.00

1.50

2.00

2.50

0.05 0.1 0.15 0.2 0.25 0.3 0.35

Strehl Ratio (K-band)

Re

lati

ve

Po

sit

ion

al E

rro

r (m

as

)

Current K2 LGS AO

+ Center Projection

+ New Laser

Relative Magnitude Error

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.05 0.1 0.15 0.2 0.25 0.3 0.35

Strehl Ratio (K-band)

Re

lati

ve

Err

or

(de

lta

ma

g) Current K2 LGS AO

+ Center Projection

+ New Laser

Keck II Center Launch + New LaserPredicted Performance for T Dwarf Binary Case

Factor of 2x improvement 6x in dynamical mass determination

R = 16.2 NGS 31” off-axis50 zenith angle

1% photometry

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Early Science Benefits from NGAO - 2

• PSF reconstruction– Collaboration with Gemini & U. Groningen to demonstrate on-axis

NGS AO PSF reconstruction on Gemini & Keck Jolissaint et al., 7736-50

– Plan to implement off-axis LGS AO PSF reconstruction with Keck– MASS/DIMM implemented (Sept/09) as a Mauna Kea facility

• Focal anisoplanatism reduction– Risk reduction to demonstrate 20% reduction using Cn2 data

• Tip-tilt vibration reduction– Risk reduction plan to prototype parametric oscillator on K2 AO

• NIR tip-tilt sensing (no object selection or AO correction)– ATI (Jun/10) funding to implement a near-IR tip-tilt sensor

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NIR Tip-Tilt SensorPredicted Performance for High Redshift Galaxies Case

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Keck AO First TAC-allocated Science Milestones

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1

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-99

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-15

Date

K2

NG

S

K2

LGS

K2

NIR

SP

AO

K2

NIR

C2

K1&

2 N

GS

Int

erfe

rom

eter

K2

OS

IRIS

K1&

2 W

FC

Upg

rade

K1

LGS

+ O

SIR

IS +

In

terf

erom

eter

K2

NG

AO

+ C

amer

a

K2

Cen

ter

Laun

ch

K2

NG

AO

Las

er 1

NIR

Tip

-Tilt

Sen

sor

Major Keck AO Science Capability Milestones

Future

Chin 7736-66; LMCT -69

In ClosingIn Closing

• Keck AO has been delivering great science

• NGAO will ensure cutting edge high angular resolution science for the US community

NGAO PD funding from NSF/AURA TSIP

Keck AO NGAO