A very deep IRAS survey at the North Ecliptic Pole

Abstract

The data from approximately 20 hours observation of the 4- to 6-square degree field surrounding the North Ecliptic Pole have been combined to produce a very deep infrared survey at the four IRAS bands. Scans from both pointed and survey observations were included in the data analysis. At 12 and 25 microns the deep survey is limited by detector noise and is approximately 50 times deeper than the IRAS Point Source Catalog, PSC. At 60 microns the problems of source confusion and galactic cirrus combine to limit the deep survey to approximately 12 times deeper than the PSC. These problems are so severe at 100 microns that we only quote flux values for locations corresponding to sources selected at 60 microns. In all, 47 sources were detected at 12 microns, 37 at 25 microns and 99 at 60 microns. Here we describe the data analysis procedures and discuss the significance of the 12- and 60-micron source count results.