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Using a source_cat.fits file in the analysis

In order to use fixed source positions in an analysis, launch ``spi_science_analysis'', un-select the catalogue extraction step and provide the name of your catalogue file in the ``spiros input catalogue'' entry field. We advise to use the standard name ``source_cat.fits'' for input catalogues.

At this stage, the complete analysis can be run again (and previous results will be overwritten). However, the catalog information is only used in spiros, and if there is no need to change other analysis parameters (such as the energy binning) only this last step may be repeated. Select ``Image analysis'', click on ``spiros'', and then on ``imaging''. You can then change the maximum ``No. of sources'' to 2 (instead of 3). This change is not really critical, but for a better comparison with the previous analysis we would like to restrict spiros to a 3 source analysis. Since the Crab source is now provided through the catalogue, we specify a maximum of 2 ``additional'' sources. Click twice on ``Ok'' to close the spiros GUIs, and ``Run'' on the main GUI. The script will execute spiros and stop.

The resulting images can be viewed with ds9 and the ``source_res.fits'' file with fv as explained before. The log file situation is now a bit more complicated. If you list the log files, e.g.,

ls -rtl spi_sa*.log

you will notice three log files. In fact, the spi_science_analysis script creates a new log file, with a ``spi_sa'' + UT date + ``.log'' naming scheme each time it is invoked. In our case, the first log file contains the output from the previous analysis (without catalogue inputs), while the second file includes the output from the catalogue extraction step. In the third file, you can find the output of the spiros ``with catalogue inputs'' run, below the usual heading

================================================================================
=                                                                              =
=         Summary of results from SPIROS-9.3.6 in IROS analysis mode           =
=                                                                              =
================================================================================

Looking in some details at this log file, you will notice that spiros provides the name of the catalogue that is used, and that it is explained that one source was provided through the catalogue while two other sources have been detected. The results (images, source_res.fits, log files) are almost identical to those of the previous case. However, you will notice that the Crab position (in source_res.fits as well as in the log file) is exactly the same as the catalogue one.


next up previous contents
Next: Spectral Extraction Up: Image reconstruction with catalogue Previous: Creating a new source_cat.fits   Contents
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