Ian M George: RXTE Software & Analysis Crib Sheets

These pages are unofficial in all respects. They are primarily simply notes to myself regarding the installation on lancelot. The information is not guaranteed to be correct or up-to-date.

"Powerlaw-noline" Fits

For Set-up etc, see Spectral Analysis using XSPEC

This is the 1st of the "standard fits" that are required to be performed
(Note some of the longer commands (in red) in the left column might have line breaks introduced by your browser. Such commands should actually all be typed on one line)
xspec> @abcd_data (if not already done)
... reads in all the files
xspec> ig 0.0-3.0 5.0-7.0 15.0-** ... ignores all the data outside the ranges specified
xspec> @wabspo.xcm ... reads in an xcm defining the model
(here is an example wabspo.xcm)
xspec> new 1 0.0333 ... resets model parameter 1 to (This must be set to the value appropriate for the Galactic line-of-sight absorption - ask me)
xspec> fit 1000 ... fits the model to the data
(in this case up to 1000 fits will be performed before you are prompted as to whether you want to continue)... obviously continue until the best-fit is found.
xspec> log abcd_noline_wabspo.log (assuming everything works OK)
... open a log file (to save the important results)
xspec> show all ... shows all the info
xspec> error 2.30 2 3 ... performs an error analysis on parameters 2 and 3 (with chimin+2.30; 68% confidence errors for 2 interesting parameters)
xspec> flux 2.0 10.0 ... writes out the 2-10 keV flux
xspec> sa mo abcd_noline_wabspo ... saves the model & best-fitting parameters for later use
xspec> log none ...closes the log file
xspec> no 4.0-8.0 ... "notices" the data in the "Fe band" (5-7 keV) previously ignored
xspec> ip eeufs ... fire up QDP and display the data & model in "nuFnu"
PLT> we abcd_noline_wabspo_eeufs.qdp ... writes out the data & model to a file
PLT> quit ... quits QDP/PLT - returns you back to xspec
xspec> ip rat ... fire up QDP and display the data/model ratio
PLT> we abcd_noline_wabspo_rat.qdp ... writes out the data/model ratio to a file
PLT> quit ... quits QDP/PLT - returns you back to xspec
xspec> exit (if you're finished)... exits xspec


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