ACTIVITY TITLE: IR Photometric Zero Points
ID: WFC3-38 (11451)
APPLICABLE SMOV REQUIREMENTS: WFC3 will provide high photometric performance over the full wavelength range covered by the instrument, with filter limiting magnitudes of at least 25.5 (J), and 24.3 (H) mag. WFC3 will provide high photometric stability, with the variation over 1 month being less than 1% from 1-2 microns.
DESCRIPTION: Observe one of three blue photometric standards (G191B2B, GD153, or GD71) and one red photometric standard (P330E), in each of the WFC3/IR filters.
Obtain two short images in each of these filters, using subarrays, with a small dither
(~10.5 pixels) between exposures, allowing rejection of cosmic rays and detector artifacts. To monitor stability in 5 key filters (F105W, F110W, F125W, F140W,
F160W), a subset of these observations will be repeated on timescales of 1, 7, and 30 days.
IMPLEMENTATION METHOD: Phase II and SMS.
DEPENDENCIES: WFC3-22 (IR Fine Alignment)
DURATION: 8 orbits
DATA REQUIREMENTS: 116 128x128 pixel images with 7 non-destructive reads per image.
ANALYSES & EXPECTED RESULTS: Aperture photometry and comparison to expectations from both thermal vacuum tests and component throughputs.
COMMENTS: None.
AUTHOR/telephone/email: Tom Brown tbrown@stsci.edu
x4902
DATE: 12/11/07