W. M. Keck Observatory Update

1

W. M. Keck Observatory Update

Randy Campbell

Photo Credit: Subaru Telescope28 May 2005 UT

12 Oct 2009 R. Campbell2

Detectors for Astronomy

Outline

Keck Highlights•Recent Projects

•LRIS, Low Resolution Imager / Spectrometer •NGWFC, Next generation wavefront controller•Current Projects•MOSFIRE, Muliti Object Spectrometer for InfraRed Exploration•K1 Laser Guide Star AO

•Future projects•NGAO, Next Generation Adaptive Optics•KCWI, Keck Cosmic Web Imager



Photo credit: Ed Stevens



Instrumentation• 8 science instruments

– Optical and infrared imagers, spectrometers

– 6 seeing limited– 3 adaptive optics (AO) assisted

• Keck-Keck Interferometer– Multiple configurations– AO assisted



LRIS – R Upgrade• Instrument age: 16 years,

– Blue side age (Two 2kX4k Marconi CCDs): 7 years• June 2009, new red side, mosaic of two LBNL 2k×4k high-

resistivity CCDs• QE improvement• No Fringing • New dewar, focus mechanism,

CCD electronics & software• Smooth LRIS-Red operations during several science runs



LRIS-R Read Noise, Dark Currentand Radiation Trails

Read Noise Dark Current

[DN] [e-] [e-/px/hr]

~4.1 ~4.0 1.7*

Average channel* Upper Limit



LRIS-R R-Band ImageBefore and after flat fielding

QE variations About 1% residual after flattening



Next Generation WaveFront Controller, NGWFC

• Commissioned in 2006– KI and KII

• Based on the CCD-39 – upgrade path to the CCID-56

• SciMeasure camera– Maximum 2.4 kHz frame rate

• MicroGate Real-time Controller• Significant improvement in

performance and reliability – Frame rate– Dark current– Read Noise– Charge Diffusion (MTF)

• Interface to existing AO system



Wave FrontControllerInterface

(WIF)

Wave FrontProcessor

(WFP)

Wave FrontControllerCommandProcessor

(WCP)

TelemetryRecorder /

Server(TRS)

Wave FrontSensor(WFS)Camera DM

high voltageamp (HVA)

NGWFC Real-Time Controller

Uplink tip -tiltmirror controller

(UTTC)

STRAPtip-tilt sensor& controller

Uplink tip -tiltclosed-loop

mirror positioner(UTT CLMP)

Downlink tip -tiltclosed-loop

mirror positioner(DTT CLMP)

Downlink tip -tiltmirror

(DTTM)

Uplink tip -tiltmirror

(UTTM)

Deformablemirror(DM)

Async command/control data

Real-time control data

Real-time telemetry data

Async telemetry queries/data

Provided by Microgate

Provided by CARA/WMKO

Existing interfaces to be reused

Downlink tip -tiltmirror controller

(DTTC)

UTT Controller

DTT ControllerWave FrontControllerInterface

(WIF)

Wave FrontProcessor

(WFP)


(WCP)

TelemetryRecorder /

Server(TRS)



-


(UTTC)







(DTTM)


(UTTM)










(DTTC)

UTT Controller

DTT Controller

NGWFC Real Time Controller

AO SCTip/Tilt Offloading

Focus Offloading

Coma Offloading

DAR

LGS Focus Manager

User Tools

Performance Monitors

Reconstructor

Calibration Tools

Optimization Tools

Control Loop Optimizer

Centroid Gain Estimator

TSS Focus

Observing Tools

KAT / IF Interface

Wave FrontControllerInterface

(WIF)

Wave FrontProcessor

(WFP)


(WCP)

TelemetryRecorder /

Server(TRS)



NGWFC Real-Time Controller


(UTTC)







(DTTM)


(UTTM)










(DTTC)

UTT Controller

DTT ControllerWave FrontControllerInterface

(WIF)

Wave FrontProcessor

(WFP)


(WCP)

TelemetryRecorder /

Server(TRS)



-


(UTTC)







(DTTM)


(UTTM)










(DTTC)

UTT Controller

DTT Controller

NGWFC Real Time Controller

AO SCTip/Tilt Offloading

Focus Offloading

Coma Offloading

DAR

LGS Focus Manager

User Tools

Performance Monitors

Reconstructor

Calibration Tools

Optimization Tools

Control Loop Optimizer

Centroid Gain Estimator

TSS Focus

Observing Tools

KAT / IF Interface

NGWFC Block Diagram



Image QualityStrehl vs. Magnitude

NGSAO

LGSAOFWHM 49mas

NGSAO

LGSAO



Key LGSAO Performance Areas

• Wave Front Controller – 1 kHz BW with laser– 20x20 sub-apertures

• STRAP , R < 19mag • Truth sensor (LBWFS)

– 20x20 Shack-Hartman• Laser brightness ~9-10 Rmag

– Spot elongation, manageable problem

– Typical spot 2.0 x 2.2 arcsec– Good up tip tilt (UTT) performance

• Regular Calibrations– Once per run– Daily afternoon check

• On Sky Optimization• Continuous Improvements to the

System

Side Projected Spot Elongation



Outline


•LRIS, Low Resolution Imager / Spectrometer •NGWFC, Next generation wavefront controller•Current Projects•K1 Laser Guide Star AO•MOSFIRE, Muliti Object Spectrometer for InfraRed Exploration




Keck I LGSAO

• Motivation– Improved performance– Greater flexibility – LGSAO with IF

• Brighter LGS AO spot– Laser: 20W (K1) vs. 14W (K2)– Mode-locked quasi-CW– Improved Na coupling

• Fiber beam transport (Mitsubishi) • Center projection (Galileo Avionica)

– Spot elongation reduced by 2x– LGS aberrations symmetric & not a function of pupil angle

• Science Instrument: – The IR integral field spectrometer, OSIRIS, moved from Keck II

• Science operation expected fall 2010

LMCTI solid state laser



MOSFIRE: Multi-Object Spectrometer for Infra-Red Exploration

• PIs: Chuck Steidel, CIT, Ian McLean, UCLA• Wide field (6’x6’) • Multiplex

– Configurable Slit Unit– 46 slits

• Each 7.3" long.

• Delivery: summer 2010• Keck I Cas focus



MOSFIRE• Detector 2048 x 2048 Teledyne Scientific Hawaii-2RG and

ASIC; 18 μm pixels, long-wavelength cutoff @2.5 μm• Guiding Optical CCD guider• Wavelength coverage 0.975 to 2.40 μm; Y, J, H, K• Spectral Resolution Rθ=2290 ⇒ R=3270 w/0.7" slit, (2.9

pixels) • Pixel Scale 0.18" in imaging mode • Field Size 6.12' slit length, 6.14' field for imaging



Cryogenic Configurable Slit mask Unit (CSU):Swiss Centre for Micro-

Electronics (CSEM).

Masking Bars

IndexingStage



MOSFIRE



NIRCTo be decommissioned in Feb 2010

• Keck I First Light instrument• 256^2 InSb (SBRC)• 38” x 38” FOV• Most sensitive Near IR instrument

for 17 years • PI: Keith Matthews, Caltech



Outline


•LRIS, Low Resolution Imager / Spectrometer •NGWFC, Next generation wavefront controller•Current Projects•K1 Laser Guide Star AO•MOSFIRE, Muliti Object Spectrometer for InfraRed Exploration




NGAO NGAO Next Generation AONext Generation AO

Key new capabilities Key new capabilities

1.1. Improved near-IR performanceImproved near-IR performance• Strehls 80% at K)• Lower backgrounds improved sensitivity• Improved PSF stability & knowledge improved

photometry, astrometry & companion sensitivity2.2. 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

3.3. Increased sky coverageIncreased sky coverage• Improved tip/tilt correction Improved tip/tilt correction improved sky coverage improved sky coverage• Broader range of science programsBroader range of science programs



NGAO Conceptual Design



NGAO Detectors

• The system is envisioned to have four types of wavefront sensors (WFS), namely, – 1 NGS WFS– 7 LGS WFS’s, – 3 Low Order IR WFS’s

• (2TTs and 1 TT Focus and Astig),

– 1 High Order truth sensor– Acquisition and diagnostic cameras – Plus science instruments



KCWI: Keck Cosmic Web ImagerChris Martin, Anna Moore, M. Matteuzski, P. Morrissey, D. Chang, S. Rahman

Science Applications (examples)① Map circum-galactic medium 2<z<7② Map circum-QSO medium③ Map z~6 reionization bubbles④ Composition & age of stellar remnants

(halos, intracluster light)

Integral Field Spectrograph: (8-30) arcsec x 20 arcsec

R~1000-20,000 spectrograph 2 channels, 0.35-1.0 μm coverage Flexible sampling, FOV, resolution High efficiency system (~30%) Designed for low surface brightness

emission Designed for precision sky

subtraction Keck II Nasmyth (likely) LBL High Resistivity CCDs

⑤ Low mass/surface brightness universe

⑥ Galaxy kinematics & stellar pops

⑦ Strong lens systems⑧ GRB/SNe host properties⑨ Galactic superwinds/feedback

3D, Low Surface Brightness Spectroscopy at Keck3D, Low Surface Brightness Spectroscopy at Keck



Acknowledgements

• Jim Lyke, WMKO• Erik Johannson, WMKO• Paul Stomski, WMKO• Marcos VanDam, WMKO• Marc Kassis, WMKO• Chris Martin, Caltech• Connie Rockosi, UCSC• James Larkin, UCLA• Chuck Steidel, CIT• Ian MacLean, UCLA• Thomas Stalcup, WMKO• Peter Wizinowich, WMKO

• www.keckobservatory.org



Thank You

W. M. Keck Observatory Update

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