Title: The Cosmic Radio Background: Recent Measurement and Implications
Abstract:
Results from the ARCADE 2 project reveal for the first time an extragalactic radio background that is brighter than some had assumed, in excess of the integrated contribution of discrete radio sources that have been characterized by interferometric surveys to their current flux limits.
The origin of the radio background has thus provoked some debate. Given what is known from an analysis of radio source count surveys and constraints from the other cosmological backgrounds, we have developed a model to explain the radio background which has interesting astrophysical implications.
First I will present the measurements performed by the balloon-borne ARCADE 2 experiment which can be combined with previous radio data. Then, I will discuss how existing constraints disfavor some explanations of the radio background that have been proposed, and present the case that the background is produced largely by the radio emission of ordinary star forming galaxies above redshift 1 characterized by an evolving radio to far-infrared correlation.