Thursday, March 06, 2008

more minor xspec patches

12.4.0m The start-up statistic, method, and weight settings in the user's Xspec.init file are effectively ignored. Instead these always start with Xspec's hardcoded default settings (chisq, leven, and standard respectively). Our thanks to Maurice Leutenegger for pointing this out. Report added on Mar 05, 2008.

12.4.0n If the precise best-fit values are input as starting parameter values to a Levenberg-Marquardt fit, for certain data sets and models the fit may run through a large number of redundant loop iterations and produce "SVDCMP" warning messages. Our thanks to Jeremy Sanders for pointing this out. Report added on Mar 06, 2008.

12.4.0o For xmmpsf and suzpsf mixing components, Xspec is unable to parse RA and DEC strings with colon delimiters (entered with the xset command). Report added on Mar 06, 2008.

Note also the there is a problem with suzpsf for all options except that of assuming the surface brightness distribution is centered on the middle of the WMAP. This issue arises because the model was written when the Suzaku XIS spectra used sky coordinates in their WMAP. Since late 2006 we have used detector coordinates but due to an oversight the suzpsf model was not updated.

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