The program spf

Alternatively, Ginga spectral files (and data cubes) can be analysed using the program spf, which was developed at Leicester (further information about spf and its command syntax are made available via the WWW ). Before fitting a spectrum, the program group must be run to specify the range and binning pulse height data to be used in the spectral fitting. The ranges of data channels and binning within the ranges are specified in pulse height channels not intrinsic instrument channels. The data in the file are not rebinned but the ranges etc. specified are saved as data objects in the file and used by the spectral fitting program spf.

The following example specifies that pulse height channels 4-32 (corresponding to energies 2-20 keV for normal high voltages; see table 6 ) are to be used in the fit. Channels 21-32 are summed together during the fit.

qcl>group

** GROUP Version 1.1 Mon Aug 11 17:55:14 1997 **
 
SPF_PFILE Input file name =mkn335_91a.phad
   SPF_PFILE: mkn335_91a.phad
   Number of time intervals 1
   Number of data bins per IDENT 48
   Number of instrument bins per IDENT 64
   Number of IDENTs 2
   Specify grouping in data bins 1-48
SPF_NRAN Number of subscript ranges (windows) = 1 =2
SPF_ILO001 Low edge of range = 1 =4
SPF_IHI001 High edge of range = 48 =20
SPF_IBIN001 Bin size within range = 1 =
SPF_ILO002 Low edge of range = 4 =21
SPF_IHI002 High edge of range = 20 =32
SPF_IBIN002 Bin size within range = 1 =2
SPF_GDUMP Dump re-binned data into file (Y/N) = No = 
qcl>

• Defining the spectral model
• Fitting the data
• Displaying the spectral fit