CaltechAUTHORS
Published January 1, 2010 | Version Published
Journal Article Open

Pixel-based correction for Charge Transfer Inefficiency in the Hubble Space Telescope Advanced Camera for Surveys

Creators

  • 1. ROR icon Royal Observatory
  • 2. ROR icon Fermilab
  • 3. ROR icon Lawrence Berkeley National Laboratory
  • 4. ROR icon Jet Propulsion Lab
  • 5. ROR icon California Institute of Technology
  • 6. ROR icon Space Telescope Science Institute
  • 7. ROR icon Stanford University

Abstract

Charge Transfer Inefficiency (CTI) due to radiation damage above the Earth's atmosphere creates spurious trailing in Hubble Space Telescope (HST) images. Radiation damage also creates unrelated warm pixels – but these happen to be perfect for measuring CTI. We model CTI in the Advanced Camera for Surveys (ACS)/Wide Field Channel and construct a physically motivated correction scheme. This operates on raw data, rather than secondary science products, by returning individual electrons to pixels from which they were unintentionally dragged during readout. We apply our correction to images from the HST Cosmic Evolution Survey (COSMOS), successfully reducing the CTI trails by a factor of ~30 everywhere in the CCD and at all flux levels. We quantify changes in galaxy photometry, astrometry and shape. The remarkable 97 per cent level of correction is more than sufficient to enable a (forthcoming) reanalysis of downstream science products and the collection of larger surveys.

Additional Information

© 2009 The Authors. Journal compilation © 2009 RAS. Accepted 2009 September 1; received 2009 August 31; in original form 2009 August 5. The authors gratefully thank Chris Bebek, Paul Bristow, Marissa Cevallos, Nick Cross, Kyle Dawson, Andy Fruchter, Nigel Hambly, Mike Lampton, Michael Levi, Max Mutchler, Natalie Roe, George Seabroke, Suresh Seshadri, Patrick Shopbell, Tim Schrabback and Roger Smith for sharing their expertise. The HST ACS CTI calibration programme is funded through NASA grant HST-AR-10964. The HST COSMOS Treasury programme was funded through NASA grant HST-GO-09822 with P.I. Nick Scoville. RM is supported by STFCAdvanced Fellowship PP/E006450/1 and FP7 grant MIRG-CT-208994. AL acknowledges support from the Chamberlain Fellowship at LBNL and from the Berkeley Center for Cosmological Physics. This work was based on the observations with the NASA/ESA HST, obtained at the Space Telescope Science Institute, which is operated by AURA Inc, under NASA contract NAS 5-26555.

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Additional details

Identifiers

Eprint ID
17262
Resolver ID
CaltechAUTHORS:20100121-093145806

Funding

Science and Technology Facilities Council (STFC)
PP/E006450/1
Seventh Framework Programme (FP7)
MIRG-CT-208994
Chamberlain Fellowship at LBNL
Berkeley Center for Cosmological Physics
NASA
HST-AR-10964
NASA
HST-GO-09822
NASA
NAS 5-26555

Dates

Created
2010-01-26
Created from EPrint's datestamp field
Updated
2021-11-08
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Physics Department