FOS ISR 150



FOS Spectropolarimetry

A. Storrs, A. Koratkar, C. Keyes, H. Bushouse, M. De La Peņa, and R. Allen

			May 1998



			Abstract



This is the comprehensive closeout ISR on FOS spectropolarimetry. The various 
sections of this document contain the detailed theory of spectropolarimetry 
with the FOS, including the correction for COSTAR-induced polarization, a 
discussion of the format of the FOS polarimetry files, a description of how to 
manipulate the data with the STSDAS spec_polar package, and a discussion of 
the accuracy of the calibration, which at the 1s level is about 0.3 percent 
for linear polarization pre-COSTAR and 0.5 percent post-COSTAR. How the post-
COSTAR polarization files (PCP files) are made and how the recalibration of 
archived data has been conducted, as well as a summary of general conclusions 
are also presented. An appendix containing the IRAF script used in producing 
the PCP files is included for completeness.