Improving HST/WFC3 photometric calibration
Abstract
I will discuss improvements in the photometric calibration of the Wide Field Camera 3 (WFC3) imaging channels based on the analisys of 6 years of standard star observations acquired between 2009 and 2015. Observations of the three white dwarf standard stars, GD 153, GD 71, and G191B2B and of the G-type star P330E were obtained at multiple dither positions . Departing from previous practice, chip-dependent inverse sensitivities for the WFC3/UVIS channel are computed at r=10 pixels for the 42 full frame filters (excluding the 20 quad filters); and these data also provide encircled energy fractions as a function of filter. Chip-dependent inverse sensitivities differ on average by 3% from previous computations, primarily due to drizzling effects. I describe the UVIS 2.0 (chip-dependent) philosophy and discuss the esults in the context of prior photometric calculations. Further, I will also discuss the status of the WFC3/IR photometric calibration, in view of updated linearity corrections and updated dark reference files.
- Publication:
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American Astronomical Society Meeting Abstracts #229
- Pub Date:
- January 2017
- Bibcode:
- 2017AAS...22920604D