ROSAT Status Report #133

[FLOWERS ON THE RAZOR WIRE <TURNER@LHEAVX.GSFC.NASA.GOV>]

		   ROSAT Status Report # 133
	
			Dec 12 1995


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	         Bug in the XSPEC gain command

There is a bug in the use of the gain command in XSPEC when analyzing ROSAT
PSPC data. This bug is such that the fit result after doing a gain shift
should not be trusted. Gain command bugs exist in xspec versions 9.00 and
earlier. This will be fixed in the next XSPEC release (probably summer of 1996).
Anyone wanting to use the gain command on ROSAT PSPC data before then
should get version 9.00 and install the fixed subroutine (do not try to fix
older versions of xspec). Users are  welcome to ftp from legacy the file
software/xanadu/xandis/spectral/xspec/src/data/gnshft.f and use it to
replace their copy. After ftp'ing the new file they should rebuild XSPEC. 

Note that this bug does not affect the use of the gain command with ASCA
data. We apologise for any inconvenience caused. 
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