Calibration Workshop 22 July 2010J.W. MacKenty Page 1 Performance and Calibration of Wide Field Camera 3 John W. MacKenty, STScI Randy A. Kimble, NASA/GSFC

Calibration Workshop 22 July 2010 J.W. MacKenty Page 1

Performance and Calibration of Wide Field Camera 3

John W. MacKenty, STScIRandy A. Kimble, NASA/GSFC

andThe WFC3 Team



Wide Field Camera 3

• A 4th generation science instrument for the Hubble Space Telescope

• Provides HST with powerful imaging capabilities for the future– Visible light capabilities to complement ACS

• More filters, smaller pixels, new CCDs– Greatly improved (>20x) near UV and near IR performance

• Built as a Facility Instrument by GSFC & STScI– Science Oversight Committee and Science Integrated Product Team– Contractor team “reusing” HST designs, hardware, and knowledge

• Instrument is performing very well– All redundant electronics running on primary side– Complex thermal system stable at planned setpoints (especially the critical

detector temperatures)– Image quality and photometric stability are excellent– Optical, mechanical, and thermal systems demonstrate outstanding stability– No operational liens or issues


WFC3 Timeline

• 1997: SM4 Instruments AO selected COS for a mid-2002 launch.• 1997:HST Mission extended from 2005 to 2010.• 1998: WFC3/UVIS approved with a mid-2003 launch date.• 1999: Infrared Channel added on community recommendation.

• 2003: Columbia lost; SM4 then planned for early 2005 launch.• 2003: WFC3 optical bench delivered to GSFC by Ball Aerospace.• 2004: SM4 cancelled in January.

• 2004: Thermal Vacuum Test #1 (IR Focal Plane #64; Flight CCDs)• 2004-5: Re-design of WFC3 to support robotic servicing with HST Gyros

• 2007: Thermal Vacuum Test #2 (IR Focal Plane #129; Backup CCDs)• 2008: Thermal Vacuum Test #3 (IR Focal Plane #165; Flight CCDs)• 2008: Delivered WFC3 to KSC in August for October 2008 Launch• 2009: Launched in May 2009 following delay due to HST SI C&DH


Team Accomplishment• The WFC3 Science Integrated Product Team (2009)• Sylvia Baggett• Elizabeth Barker• Tiffany Borders• Howard Bushouse• Tomas Dahlen• Linda Dressel• Susana Deustua• Michael Dulude• George Hartig• Bryan Hilbert• Robert Hill (GSFC)• Jason Kalirai• Jessica Kim Quijano• Randy Kimble (Instrument Scientist, GSFC)• Vera Kozhurina-Platais• Knox Long• John MacKenty (Deputy Instrument Scientist)• Brian McLean• Peter McCullough• Cheryl Pavlovsky• Larry Petro• Nor Pirzcal• Abhijith Rajan• Adam Riess• Elena Sabbi• Alex Viana• Michael Wong

• Past Science IPT Members• Wayne Baggett• Howard Bond• Tom Brown• Laura Cawley• Ed Cheng (GSFC, now

Conceptual Analytics)• Ilana Dashevsky• Don Figer• Mauro Giavalisco• Shireen Gonzaga• Christopher Hanley• Ron Henry• Pat Knezek• Ray Kutina• Casey Lisse• Olivia Lupie• André Martel• Neill Reid• Massimo Robberto• Michael Robinson• Megan Sosey• Massimo Stiavelli

• The WFC3 Scientific Oversight Committee• Bruce Balick, University of Washington• Howard E. Bond, Space Telescope Science Institute• Daniela Calzetti, Space Telescope Science Institute• C. Marcella Carollo, Institute of Astronomy, ETH, Zurich• Michael J. Disney, Cardiff University• Michael A. Dopita, Mt Stromlo and Siding Spring Observatories• Jay Frogel, AURA• Donald N. B. Hall, University of Hawaii• Jon A. Holtzman, New Mexico State University• Randy Kimble, NASA Goddard Space Flight Center (ex officio)• Gerard Luppino, University of Hawaii• Patrick J. McCarthy, Carnegie Observatories• John MacKenty, Space Telescope Science Institute (ex officio)• Robert W. O’Connell, University of Virginia (Chair)• Francesco Paresce, European Southern Observatory• Abhijit Saha, National Optical Astronomy Observatory• Joseph I. Silk, Oxford University• John T. Trauger, Jet Propulsion Laboratory• Alistair R. Walker, Cerro Tololo Interamerican Observatory• Bradley C. Whitmore, Space Telescope Science Institute• Rogier A. Windhorst, Arizona State University• Erick T. Young, University of Arizona

• WFC3 Management, Engineering, and Contractor Teams– Thai Pham and Jackie Townsend, GSFC Instrument Managers– GSFC Engineering Teams in Codes 400, 500, and 600 (plus Code 300 reviewers)– Ball Aerospace, Swales Aerospace (now ATK), Teledyne, E2V, and many others

• By my estimate 300-400 people made significant contributions to the development of Wide Field Camera 3




Calibration Strategy

• SMOV (Commissioning Activities)– Primary Requirement: safely start science program at earliest date

– Start monitoring of WFC3 performance

• Cycle 17 Calibration– Basic Calibrations: Detectors, Photometry, Flats, Astrometry, etc.

– Trend Instrument: stability improved calibration over time

– Understand instrument

• Cycle 18 Calibration– Plan now in development: input welcome


WFC3 SMOV Program

• Three phases:– Engineering: Instrument Performance Nominal

• Complete except for TEC setpoint verification ongoing

– Optical Alignment: met expectation (one extra iteration in each channel)

– Science performance and calibration verification• Demonstrates that WFC3 can be calibrated to anticipated levels

• Early calibration of geometric distortion for EROs successful

• 43 distinct SMOV Activities following SM4– 4 used engineering telemetry data only

– 39 required a total of 429 visits.

– Total number of Images: ~4100 (completed September 11)

• Results– Viewgraph stack posted Sept 9, 2009 with results of each activity

– Instrument Science Reports published on most proposals

– No major surprises (but throughput 5-15% above pre-launch predictions)


Cycle 17 Calibration Plan

• WFC3 Cy17 Calibration Plan– Covers 15 months starting 1 August 2009

– Scope: 35 proposals, 249 external orbits, ~2220 internal orbits

– Supplemental Program (2/2010): 16 ext/35int orbits

• Three ISRs describe our approach in key areas– ISR 2009-07: Overview of the WFC3 Cycle 17 Detector Monitoring

Campaign by M. H. Wong et al. 29 May 2009

– ISR 2009-06: WFC3 Calibration Using Galactic Clustersby E. Sabbi et al. 08 Sep 2009

– ISR 2009-05: The Photometric Calibration of WFC3: SMOV and Cycle 17 Observing Plan by J. S. Kalirai et al. 12 Jun 2009

• Overview/Summary ISR– ISR 2009-08: WFC3 Cycle 17 Calibration Program by S. Deustua et al. 18 Feb 2010


Cy17 Supplemental Calibrations

• IR Subarray Anomaly

• Persistence Characterization

• UVIS Stray Light

• F336W zeropoint and flat test

• IR Linearity in Subarrays

• UVIS Image Skew Verification

• CCD Fringe Calibration

• Tungsten Lamp Warmup

• Photometry with Spatial Scans


Major Calibration Topics

• Photometric Zero-points (Jason Kalirai talk)

• Flat Fields (Elena Sabbi and Nor Pirzkal talks)– Ground external flats have ~4% gradient: Omega Cen L-Flats

• First versions are appearing on the www site as “alpha releases”

– High spatial frequencies appear stable (pre/post launch int flats)

– Future efforts in sky (IR only) and earth flats

• Astrometry & Geometric Distortion (Vera Kozhurina-Platais talk)– 10 UVIS and 5 IR Filters have multiple observations of star fields

– IDCTAB solutions on www as “alpha release” with older single filter solutions in CDBS/OPUS

• Detector bias, dark, linearity, bad pixels, etc (Bryan Hilbert talk)

• CALWF3 pipeline (Howard Bushouse talk)


Main Calibration Issues

• IR Detector Persistence (Knox Long talk)– Unlike NICMOS the SAA is not a problems (flush is on in SAA)– Bright targets leave residual images for several orbits– STScI working several paths

• Linearity of IR detector depends upon flux (Adam Riess talk)– “Count Rate Non-Linearity” aka “Bohlin Effect”– Smaller effect than NICMOS but ultimate calibration expectation higher

• Ongoing calibration effort UVIS detector– Radiation effects on CTE (Vera Kozhurina-Platais poster)

• Planning to implement Change Injection for Cycle 19

– Ability to do photometry with saturated stars (Ron Gilliland poster)– Correction for fringing in red light (Mike Wong talk)

• IR Grisms are very popular (Harald Kuntschner talk)– Planned phaseout of ST-ECF support and transfer to STScI in Dec 2010– Broad variety of science will test this capability


Cycle 18 Grism Usage

• Large complement of CY18 GO IR Grism observations

• ~100 orbits in MCT (Riess) TOO for SN1aID PI Orbits Title

12177 Van Dokkum 248 3D-HST: A Spectroscopic Galaxy Evolution Treasury

12181 Deming 115 The Atmospheric Structure of Giant Hot Exoplanets

12190 Koekemoer 32 WFC3/IR Spectroscopy of the Highest Redshift Black Hole Candidates

12203 Stanford 30 Rest Frame Optical Spectroscopy of Galaxy Clusters at 1.6<z<1.9

12217 Lucas 6 Spectroscopy of faint T dwarf calibrators: understanding the substellar mass function and the coolest brown dwarfs

12230 Swain 18 The effect of radiation forcing on an exoplanet atmosphere

12247 Tanvir 18x3 Identifying and studying gamma-ray bursts at very high redshifts

12251 Berta 24 The First Characterization of a Super-Earth Atmosphere

12283 Malkan 280par WFC3 Infrared Spectroscopic Parallel Survey WISP: A Survey of Star Formation Across Cosmic Time

12314 Apai 24 Mapping Brown Dwarfs: The Evolution of Cloud Properties Through the L/T Transition


Posters at this Workshop

• W1 UVIS Detectors – Sylvia Baggett• W2 Image artifacts – Michael Dulude• W3 UVIS linearity – Abhijith Rajan• W4 UVIS linearity beyond saturation – Ron Gilliland• W5 DCL measurement of IR count rate non-linearity – Bob Hill• W6 L-Flats – Jennifer Mack• W7 CTE monitoring – Vera Kozhurina-Platais• W8 PSF measurements – Linda Dressel• W9 Example of IR Grism reduction – Martin Kuemmel• W10 IR Filter Wedge – Elena Sabbi & Tiffany Borders• W11 Dither and Drizzle Strategies – Max Mutchler


Information Resources

• WFC3 Instrument Handbook– v1.0 December 2007; v2.0 January 2010; v2.1 June 2010

• WFC3 Data Handbook (v1.0 January 2009)

• WFC3 Space Telescope Analysis Newsletter (STAN)– #1 September 2009; #2 December 2009; #3 March 2010; #4 June 2010

• “Late Breaking News” on www.stsci.edu/hst/wfc3– “Alpha Release” of calibrations [feedback requested!]

• Instrument Science Reports– Cover design decisions, SLTV#1, #2, #3, SMOV, and Cy17

– 235 reports available at http://www.stsci.edu/hst/wfc3/documents/ISRs/


WFC3 First Light Images

Calibration Workshop 22 July 2010 J.W. MacKenty Page 18GSFC System Eng. Seminar, December 8, 2009 Performance and Early Results of Wide Field Camera 3 R. Kimble (NASA/GSFC)


Documents

Calibration Workshop 22 July 2010J.W. MacKenty Page 1 Performance and Calibration of Wide Field Camera 3 John W. MacKenty, STScI Randy A. Kimble, NASA/GSFC