Instrument Science Report 2009-06:
On-Orbit Photometric Calibration of the WFPC2 Linear Ramp Filters
J. Biretta, P.L. Lim, M. McMaster, and S. Gonzaga
December 17, 2009
As part of the WFPC2 close-out calibrations, we have revised the SYNPHOT throughput curves for the linear ramp filters using on-orbit photometry of a standard white dwarf, EGGR-102 (GRW +70 5824). Comparison of the new on-orbit data and previous groundbased calibrations show differences up to ~20%. The accuracy of the new throughput table is expected to be ~2% at most wavelengths, though as noted herein, some wavelengths with limited or no on-orbit data will have poorer accuracy. The new ramp filter throughput file has been delivered to CDBS and will be used in reprocessing the WFPC2 archive.
The Complete Paper (PDF 4.4 MB) is available.