The charge transfer efficiency (CTE) of the ACS CCDs (WFC and HRC)
is declining as damage from the space radiation environment accumulates.
Here we provide information about our efforts to monitor CTE,
and methods of mitigating and calibrating it.
The ACS/WFC CTE Correction Calculator corrects ACS/WFC aperture photometry for CTE losses
using the most recent formula from Chiaberge's ISR 2012-05 and updated coefficients
based on cycle 20 calibration data.This tool is only calibrated for photometry obtained after SM4 in May 2009.
For pre-SM4 data, please see Chiaberge et al. 2009 (ISR 2009-01),
or use pixel-based CTE-corrected files obtained from MAST.
A new accurate CTE photometric correction formula for ACS/WFC (ISR 12-05)
CTE White Paper, June 29, 2012
Empirical Pixel-Based Correction for Imperfect CTE (ACS ISR 2010-03)
Pixel-based correction for CTI in the HST ACS (ACS ISR 2010-01)
Updated CTE photometric correction for WFC and HRC (ACS ISR 2009-01)
Internal monitoring of ACS CTE (ACS ISR 2005-03)
Time Dependence of ACS WFC CTE Corrections for Photometry and Future Predictions (ACS ISR 2004-06)
Elevated temperature measurements of ACS CTE (ACS ISR 2004-04)
WFC radiation test (ACS ISR 2000-09)
CTI over the History of the ACS WFC poster for AAS Meeting, January 2011
Post-SM4 ACS CTE poster for AAS Meeting, January 2010
ACS CTE poster for AAS Meeting, January 2003
Internal monitoring of ACS CTE:
Post-SM4 EPER and FPR for WFC
Pre-SM4 EPER and FPR for WFC and HRC
Internal (EPER/FPR) CTE programs:
External (47 Tuc) CTE programs:
CTE Working Group (1999-2000)
Group membership and charter
Workshop at STScI in January 2000
HST CTE in the second decade (WFC3 ISR 2001-05)
Pixel-based CTE correction page for WFC
Justification for onboard FPR/EPER CTE calibration (ACS TIR 1999-03)
ACS CTE OPRs