Fitting SPI spectra using XSPEC

To extract a spectrum with the spi_science_analysis script, follow the instructions provided in Sect. . The spi_science_analysis script sets all relevant parameters in the resulting spectra, creates an appropriate response file, and links it to the spectrum.

Below is a simple example of an XSPEC spectral fitting session with a Crab spectrum (spectrum_Crab.fits).

     xspec
     cpd /xs
     data spectrum_Crab.fits
     setpl energy
     model power
     2.0
     8.0
     fit 1000
     flux 20,200
     plot ldata delchi