As discussed in section V.H.6 of the Explanatory Supplement, regions with more sources per sq. deg than the confusion limit in a given band were processed according to more stringent rules to insure the reliability of the data presented in the catalog. The regions so processed were selected on a band-by-band basis depending on the number of sources with high or moderate quality fluxes located within a 1 sq. deg bin in ecliptic coordinates. Users of the Point Source Catalog who want to know the identity of those regions may use High Source Density Bins file, which lists bin numbers, a flag called HSD which indicates which bands in a given bin were processed according to high source density rules, the ecliptic coordinates of the centers of the bins, and their lengths in ecliptic longitude. All bins have a height of 1° in ecliptic latitude.

Reference:
Infrared Astronomical Satellite (IRAS) Catalogs and Atlases, vol. 1, Explanatory Supplement, 1988, ed. C. Beichman, et al., NASA RP-1190 (Washington, DC: GPO)

Version and release date: 1984 Nov 16

• Request the High Source Density Bins File from the NDADS
• See the format of the File (in the Explanatory Supplement)