GALEX MCAT Source Density

The density of NUV and FUV sources in detector coordinates are computed for 3267 'MCAT' merged catalogs. This includes MIS single visit (no subvisits) observations only. The observations are widely spread out over time and over the sky. The exposure times range from 300 to 1700 seconds. The maps shown below are smoothed with a 5 by 5 pixel box.

The smoothed NUV source density map appears to have some azimuthal symmetry (why?), which does not appear to closely match the response map.

The smoothed FUV source density map does not have the same 'ring' patterns as with the NUV sources, and appears to better match the FUV response map. (Note the unmasked hot spots.)

-tab February 2009