POINT SPREAD FUNCTIONS; IMAGE PROCESSING; CALIBRATING; COMPUTATIONAL GRIDS; ASTRONOMICAL PHOTOMETRY; ITERATION; QUASARS; HIGH RESOLUTION; VIBRATION; CAMERAS; SUBTRACTION
Abstract :
[en] Based upon the subtraction of TinyTim Point Spread Function (PSFs) from Principle Component Image (PC1) point-like objects, a method has been developed to determine the optimal values for the telescope jitter and the Z4 relative focus during calibration or science observations. Using these jitter and focus values, an optimal TinyTim PSF, computed over a resampled grid, is then iteratively fitted to the object, yielding an improvement in the PSF centering, more accurate photometric results and a better detection of underlying structures. Preliminary results seem to indicate that appropriate synthetic TinyTim PSFs perform as well as observed PSFs.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Remy, M.
Surdej, Jean ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astroph. extragalactique et observations spatiales (AEOS)
Baggett, S.; Space Telescope Science Inst.
Wiggs, M.; Space Telescope Science Inst.
Language :
English
Title :
WFPC2 photometry from subtraction of TinyTim PSFs
Publication date :
01 January 1997
By request :
Yes
Audience :
International
Main work title :
The 1997 HST Calibration Workshop with a New Generation of Instruments, p. 374
