Description

The analyze_ltcrv.sl script analyzes a lightcurve, e.g. created by dmextract. It performs an iterative sigma-clipping algorithm, removing those points that fall outside +/-3 sigma from the mean at each iteration until all data points are within +/-3 sigma. This algorithm is robust but not perfect; it can easily "overclean" a noisy lightcurve and should not be used blindly. The output is a graph of the lightcurve, showing suggested excluded points in red and accepted points in green, together with a list of the accepted time periods and their lengths.

The output time periods can then be used to filter the event list, either by using dmgti to create a GTI file, or directly within a DM filter expression.

The script is run from within ChIPS ("ahelp chips"), as shown in the example. To load the script:

chips> () = evalfile("analyze_ltcrv.sl")

This step is only necessary once per ChIPS session.

This script is used in the Filtering Lightcurves thread.