XMM Examples - excluding contaminating sources

In many cases, e.g. for extended sources or for background regions, single sources might contaminate the area that is examined. I this cases those contamining sources have to be excluded.

First create an image as described in the Simple Image page.
Define the regions you want to exclude as described in the select region page
use the XMM-SAS commands evselect or xmmselect to selected the contaminated regions.It works in the same way as described for the filtered event list.

So far, all contaminating sources have to be typed in the `expression' in evselect (or xmmselect) as given in the following example:

evselect table=events.fits withfilteredset=true destruct=yes keepfilteroutput=true \
expression=".not.circle(26080,26080,900,X,Y).and..not. \
circle(24850,23370,820,X,Y).and..not.circle(23700,23370,410,X,Y).and..not. \
circle(29360,27400,410,X,Y).and..not.circle(30258,26980,820,X,Y).and..not. \
circle(31250,27225,820,X,Y)" filteredset=events_clean.fits

Image from the original contaminated event file
Image created from the cleaned event file

Last change: 2002-04-22 16:50 by D. Grupe