TUNA Lunch Talk:

Jim Condon


Resolving the Radio Source Background: Deeper Knowledge Through Confusion

May 29

12:10PM, Room 230, NRAO, Edgemont Road


Nearly all extragalactic radio sources stronger than S ~ 1 mJy are powered by AGN, and most of the fainter sources are in star-forming galaxies. For the first time, the extragalactic background at 3 GHz has been resolved into discrete sources by a deep JVLA image that is confusion limited at S ~ 1 microJy. The resolved radio-source background matches the far-infrared (FIR) background at 160 microns for radio sources obeying the FIR/radio correlation, so we probably have "seen it all." Any hypothetical new population of even fainter radio sources cannot produce confusion fluctuations > 0.7 microJy/beam. This rules out galaxies as an explanation for the surprisingly high 3.3 GHz background brightness reported by the ARCADE 2 balloon experiment.