XMM-Newton Science Analysis System


omvariability (omvariability-1.6) [xmmsas_20230412_1735-21.0.0]

Algorithm

omvariability is a c++ program and works as follows:

• For each SWS file given in the list for the parameter srclistsets-
  • Read in the Right-Ascension, Declination, corrected count-rate and corrected count-rate error, instrumental magnitude and instrumental magnitude error, extension flag, confusion flag and quality flag and Source ID. Note that the last quantity identifies which unique source in an observation source-list file the source is a counterpart of. A map is used in which the key is a source ID and the value another map having its key as the OM filter and its value as a c++ vector that stores the parameters of the source from each SWS file.

• Iterate through the source IDs stored in the source map and for each one:
  • Iterate through the list of OM filters for that source and
    • If the list contains at least the number of sources specfied by the parameter minnumsources, compute variability parameters and store the parameters in another map MAP 1 that the OM filter as its key and the variability parameters as its value (stored in a structure).

  • If the user has specified that a variability plot should be produced, iterate through the computed variability parameters for each filter for the source ID and if the minimum deviation of the corrected count-rate of any source from the median value is at least equal to the value set by the input parameter minnstd, plot the source details.

• Iterate through the filters in MAP 1 and add the variability columns to the output file specified by the parameter outset.