XMM-Newton Science Analysis System
espfilt (espfilt-4.3) [xmmsas_20211130_0941-20.0.0]
This task assumes that SAS tasks cifbuild, odfingest
one of the event-list producing EPIC MOS or PN task (emchain,
epchain) have previously been run.
An error will result if the odfingest ASCII output file or the
cifbuild FITS file are not present and set using the proper SAS
environment variables or command line options.
For the Histogram Method, espfilt performs the following in sequence:
- The task checks to see if event list is present and has the
- Define corner selection criteria for evselect calls.
- Create FOV and corner images and lightcurves with evselect.
- Depending on the method selected, the proper subroutine for processing via that method is envoked.
- For the Histogram method:
- Clean lightcurve in subroutine CLEAN_LC.
Clean the light curve by creating a histogram of rate values
from the light curve, finding the most likely value, assuming
that to be similar to the mean of the quiescent rate, then
fitting a Gaussian (or poissonian, or user defined curve) to
a small window around that value in the histogram to determine
the true mean and dispersion of the quiescent background rate.
Excludes time intervals with rate higher than a multiple of
the dispersion above the mean quiescent background and excludes
good regions shorter than some (currently hardcoded) limit.
For the Ratio Method:
For both methods, each of the following is performed
- Create FOV annulus and corner annulus images and lightcurves.
- Determine Counts per pixel Ratio between the FOV annulus and corners.
- For Time Intervals within user-selected ratio threshold ranges, select data using evselect.
- Create an ASCII QDP format file.
- Run gtibuild.
- Run evselect to produce filtered, flare-free events file.
- Run evselect to produce filtered, flare-free image.
- Run evselect to produce corner-only events file.
- Run evselect to produce corner-only image.
- If PN, run evselect to produce cleaned OOT event file.
XMM-Newton SOC -- 2021-11-30