Event Details

Since as early as the 1960s astronomers have periodically noted a significant isotropic component in the radio sky. Interest in this signal was rekindled with the results of the ARCADE 2 experiment. Those results, together with previous absolutely calibrated radio measurements, show this isotropic ‘radio background’ to be several times brighter than expected with standard astrophysical considerations. There is robust debate about whether the radio background is Galactic or extragalactic in origin. Various explanations have been proposed, ranging from annihilating dark matter in cosmic filaments to supernovae of population III stars to an enhanced cosmic ray halo around the Milky Way, but it is difficult to produce the observed level of surface brightness by known processes without violating other constraints. This talk will present the current state of knowledge of the radio background and discuss the cases for and against the proposed origin scenarios.