Contribution of Infrared Galaxies to the Cosmic Background

Abstract
The far-infrared background due to a superposition of infrared galaxies of the type recently observed is computed. It is shown that these galaxies contribute an amount of energy to the universe roughly equal to that radiated by the other galaxies and produce a far-infrared background peaking beyond 50 μ. It is likely that they account for most of the observed extragalactic radio background but not the 3°K microwave background.