XMM-Newton Science Analysis System


ekstest (ekstest-2.8.1) [xmmsas_20230412_1735-21.0.0]

Algorithm

   Subroutine ekstest

     Recover parameters (File name, GTI file)
        
     Read source time series FITS file : 
        Get dataset(s) and table.
        Check important keyword consistency (notably TSTART and TIMEDEL).
        Call a warning or error if necessary.

     Recover all light curves included in table :
        Net source rates and errors and background rates and errors are recorded in arrays
        of dimension Nlightcurve * Nbins.

      For each light curve :

        Delete gaps in data (when the IEEE NaN constant is found) and outside of GTIs.

        Perform variability tests on rebinned counts and background or the net source counts and the cumulative time distribution:
           Calculate mean count rate and variance.
           Test the null hypothesis (the source is not variable) with the :
               - Kolmogorov-Smirnov test 
               - chi-squared test 
               - fractional variability amplitude test 
               - flare test
               - variation test 

     End for

     Write variability test results into header and/or to screen.
               
     Release memory.

   End subroutine ekstest