Point Source Masking

The use of point source masking is accomplished in two ways, by using mask images or source region lists produced by running the perl script cheese (see ยง 5.12). If images are of interest then a simple masking of the data can be done by using the “Swiss Cheese” images. If the desire is to remove the source contributions to spectra then the source region lists must be used in the mosspectra or pnspectra calls, which is done using a calling parameter of the tasks. If point sources are removed from the spectra in the calls to mosspectra and pnspectra they are also removed from the images, and during the image creation process (see below) the images must also be masked using the Swiss-cheese images. However, as discussed below, it is possible to exclude point sources in the spectral fits used to determine the SP contribution and then scale the results to the whole image.