A study of external galaxies detected by the COBE Diffuse Infrared Background Experiment

A comparison of the COBE1 Diffuse Infrared Background Experiment (DIRBE) all-sky survey with the locations of known galaxies in the IRAS Catalog of Extragalactic Objects and the Center for Astrophysics Catalog of Galaxies led to the detection of as many as 57 galaxies. In this paper, we present the photometric data for these galaxies and an analysis of the seven galaxies that were detected at lambda > 100 mu m. Estimates of the ratio of the mass of the cold dust (CD) component detected at T-d = 20-30 K to a very cold dust (VCD) component with T-d approximate to 10-15 K suggest that between 2%-100% of the cirrus-like CD mass can also exist in many of these galaxies as VCD. In one galaxy, M33, the DIRBE photometry at 240 mu m suggests as much as 26 times as much VCD may be present as compared to the cirrus-like component. Further submillimeter measurements of this galaxy are required to verify such a large population of VCD. We also present 10 galaxies that were detected in the sky region not previously surveyed by IRAS and that can be used to construct a flux-limited all-sky catalog of galaxies brighter than 1000 Jy with a modest completeness limit of about 65%.