Astronomy and Astrophysics – Astronomy
Scientific paper
Jul 2008
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008hst..prop11397m&link_type=abstract
HST Proposal ID #11397. Cycle 17
Astronomy and Astrophysics
Astronomy
Scientific paper
The stability and uniformity of the low-frequency flat fields {L-flats} will be studied in detail for one filter in the HRC {F475W} and WFC {F606W} using multiple dithered pointings of 47 Tucanae. By moving the same star over different portions of the detector and measuring relative changes in brightness, any spatial variations in the detector response can be measured. These star field observations will be used to verify the L-flats derived from exposures using the internal lamps {program 11374}. High quality baseline measurements of the cluster provide a catalog which is both astrometrically and photometrically well calibrated, so a full-scale geometric distortion calibration of the CCDs is not necessary. Instead, the stability of the distortion solution will be verified to about 0.2 pixels using the centroid position of stars, corrected for CTE and proper motions. These observations will also be used to verify the recently computed time-dependent skew correction. To supplement to the usual diagonal dither pattern, steps along the x and y axes will allow a simultaneous evaluation of the detector CTE. One additional long exposure {HRC} and two short exposures {WFC} will give an estimate of the CTE for different sky backgrounds. This is activity number ACS-11.;
No associations
LandOfFree
CCD Sensitivity, Geometric Distortion and FF Stability does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with CCD Sensitivity, Geometric Distortion and FF Stability, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and CCD Sensitivity, Geometric Distortion and FF Stability will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1319909