|Space Telescope Science Institute|
|WFC3 Instrument Handbook|
A.1 IntroductionThis appendix contains plots of throughputs and sensitivities for each WFC3 filter. It is organized by detector and filter. For each imaging mode the following are provided:
• Tables of color corrections ABν to go from Johnson V magnitude to AB magnitude for stellar spectra (as a function of effective temperature) and composite populations (as a function of age). The stellar spectra come from the Lejeune et al. (1997, A&AS, 125, 229) grid, and assume a surface gravity of log g = 5 and solar metallicity. The composite populations come from the “instantaneous burst” and “continuous star formation” models of Bruzual & Charlot (1993, ApJ, 405, 539), updated in 1995, assuming a Salpeter IMF spanning 0.1 to 125 solar masses.The plots presented here were derived using on-orbit data that was processed with ground-based flat field reference files. (See WFC3 ISR 2009-30 and WFC3 ISR 2009-31) These flat fields are in error by up to several percent on large spatial scales (see Sections 5.4.3 and 5.7.4.). Corrected plots, using improved flat fields, will be published at a later date. Monitoring of photometric performance over the first year of operations has shown the WFC3/UVIS detector to be stable to rms ~ 0.5% (WFC3 ISR 2010-14) and the WFC3/IR detector to be stable to rms ~ 0.5% to 1.0%, depending on filter (WFC3 ISR 2011-08).