The radio properties of galaxies with high far-infrared luminosities

Observations have been made with the Very Large Array, mainly at 5 GHz, of a sample of galaxies with high far-infrared luminosities selected from the Infrared Astronomical Satellite (IRAS) minisurvey. The surface brightnesses of the minisurvey sources are greater than those of the disks of normal galaxies but are similar to those of the central radio sources in these galaxies; the minisurvey sources, however, have much larger luminosities and physical sizes than these central sources. On the basis of the available data at all wavelengths, it is concluded that the far-infrared and radio emission from the minisurvey galaxies is caused by star formation, not by active nuclei. It is found that the size of the radio source is inversely correlated with the 60-100 micron color temperature but is independent of the far-infrared luminosity