next up previous contents
Next: Raymond Model Up: *fit* - Fit Data Previous: *fit* - Fit Data

Power Law fit to a Point Source

The power law model with galactic absorption will be applied to ROSAT data the extracted earlier The results will be stored in the _prd table in the current directory.

input files:,,

output file:

NOTE: If an RDF SASS output file is used as input to fit (name of the form: rp<ROR#> then fit looks for an accompanying source histogram file and runs without the background histogram.

NOTE: The file is not needed for the calculation of the fitted model. It is only used for the execution of fit.

  xs> fit
  Performing the Simplex minimization fit.
  observed spectrum []: rp90               # will fit ROSAT data using
                                                # the default PSPC channels, 3:34.
  model descriptor or ? for help: abs(19:21)*pow(0.5:1.5)          # IRAF will not
        # accept .5 as a valid fraction.  Numbers <1 must be entered starting with 
                                                              # a zero, e.g., 0.5.