On the origin of the radio emission in IRAS galaxies with high and ultrahigh luminosity: the starburst-AGN controversy

Abstract

In the scenario of a violent nuclear/circumnuclear starburst, the radio luminosity detected in high-luminosity (HLIRG) and ultraluminous (ULIRG) IRAS galaxies is explained as non-thermal radio emission generated in radio supernovae and their remnants, created in an ongoing massive starburst process. These supernovae and their remnants must have peak radio luminosities 100 to 1000 times the luminosity of Cas A, and thus be radio hypernovae. The presence of radio hypernovae in a circum-nuclear starburst naturally explains the radio excess observed in these regions with respect to disc H II regions, and the FIR-radio luminosity relation