Rationale

The radio synchrotron background is a newly re-appreciated astrophysical phenomenon which has been a subject of great interest to many in the community. Combining the ARCADE 2 balloon-based absolute spectrum data from 3-90 GHz with absolutely calibrated single-dish diffuse radio surveys at lower frequencies reveals a radio synchrotron excess that is several times brighter than was expected by many. The origin of the radio synchrotron background is one of the mysteries of contemporary astrophysics. Both a local (Galactic) orign and extragalactic origin scenarios pose theoretical and observational challenges. It is difficult to produce the observed level of surface brightness by known processes without violating constraints.

The existence of the radio background at the observed levels presents profound challenges for our current understanding of radio emission in the Galaxy and the universe. As demonstrated in many recent publications, there are implications for many areas of astrophysics, including cosmic ray propagation, galactic and extragalactic magnetic fields, the radio to far-infrared correlation, radio source counts, X-ray source counts, quasar luminosity functions, dark matter annihilation, polarization of foregrounds in microwave background maps, population III stars, mergers of clusters, global 21-cm measurements, and many more.

This scientific workshop will bring together the group of scientists interested in the radio synchrotron background for the first time, and will inspire new collaborations and new lines of inquiry. A workshop on the radio synchrotron background is called for given the current level of interest in exploring its origin and because it touches on so many contemporary issues in astrophysics.