[Previous] | [Session 54] | [Next]
A. W. Blain (Institute of Astronomy, University of Cambridge), V. E. Barnard (Department of Physics, University of Cambridge)
The form of evolution of dust-enshrouded galaxies is an important issue at present in cosmology. Here we consider the properties of dusty galaxies at low and moderate redshifts, and verify that the form of strong evolution that is inferred from observations of both the diffuse extragalactic background radiation and discrete galaxies discovered using the SCUBA, MAMBO and ISO instruments is compatible with the information we have from the IRAS survey about the low-redshift Universe. A strongly evolving population of merging galaxies that are luminous in the infrared, with thermal emission spectra described by dust grains at a typical temperature of 40K, were invoked to describe the properties of high-redshift dusty galaxies in recent models. The same population of galaxies are shown to provide a good description of both low-redshift mid- and far-infrared luminosity functions, and the colors of galaxies in the IRAS catalogs. We have found that galaxies with spectral energy distributions corresponding to cooler dust temperatures of about 20K, similar to the Milky Way, make a relatively small contribution to the luminosity functions of low-redshift dusty galaxies.