Explaining the Nagoya-Berkeley Submillimetre Background

Abstract

The most natural source of the Nagoya-Berkeley excess is pregalactic or protogalactic radiation reprocessed by dust. The sort of infrared galaxies observed at the present epoch could produce the energy in the excess but only if there was a large luminosity evolution. We therefore consider pregalactic radiation sources with absorption by dust which is either intergalactic or confined to galaxies which cover the sky. In this case, fitting the data requires that the reprocessing occur at a rather high redshift (z>30). It would be hard to generate enough dust at such an early epoch in the pancake or standard cold dark matter scenarios but it would be possible in a more general hierarchical clustering picture. Possible sources for the radiation would be VMOs (very massive stars whose black hole remnants may provide the dark matter in galactic halos), cosmic explosions or decaying elementary particles.