Use of spimodfit

From the user point of view, the data processing is done in 4 major steps, which all have their own options :

• Definition of the input observation data : on input, spimodfit expects the different files constituting a SPI observation (events rate, poitings, dead times, good times, energy bins and optionally background models). The energy bins can be redefined and will be processed independently. It is also possible to select a subset of the detectors in the input data. This step are usually performed via the standard OSA processing from GTI to Background levels, but ready to use data are also available at

  http://www.mpe.mpg.de/gamma/instruments/integral/www/integral-data.html

  These data are binned at high spectral resolution, therefore the user interested in point sources should rebin the energy channels using the parameters first_energy_bin, last_energy_bin, and m_energy_rebin in spimodfit .

  The background models can be collected into one single model setting the flag spi_flatfield_single to yes or limited to a maximum number (only the first n_background_loaded ones will be loaded).

  In addition to these files, the Instrument response function files (IRFs) have to be specified. More than one IRFs files can be given to handle a time dependent response, the default values are appropriately inserted in the standard parameter file.

• Definition of the fitted parameters. spimodfit can fit extended emission ('images'), point sources ('sources') and background parameters. For each of these components, the time and detector variability should be given,as well as some other fitting or normalization parameters explained below.

• Fitting options, as the minimization routines and its initialization; MCMC options are currently not implemented.

• Definition of the output files. spimodfit generates a FITS file table containing the results of the fit. By default this file contains the different sky models (original map and fitted images) and a binary table containing the fitted parameters with associated configuration and estimated errors. Optionally, it can also add an exposure map in this FITS file, create a background model for the observation, write residues of the model, light curves, spectra and an updated point source catalog into other files.