Missed Sources

Occasionally the source detection algorithms will miss an obvious source. This can happen when the source lies, for instance, in the gap between CCDs on one of the detectors. Because of this effect we recommended the simple test of using the blink function in $ds9$ to flip between the cheese image and the event sky image for each detector.

Missed sources may often be “recaptured” by modifying the mlmin or dist parameters. However, it is usually a good idea to examine the emllist.fits file closely to determine why a source has been missed before rerunning cheese. As seen below, one can modify the emllist.fits file and run a subset of the cheese routine to iterate quickly to a better solution.