Radio emission from galaxies in the Las Campanas Redshift Survey

To increase the redshift range and look-back time over which the radio lumi nosity function can be measured directly, we identified 1157 galaxies in th e Las Campanas Redshift Survey (LCRS) having isophotal (red) magnitudes m(i so) less than or equal to 18.0 with radio sources brighter than 2.5 mJy bea m(-1) in the 1.4 GHz NRAO VLA Sky Survey (NVSS). Since the NVSS has 45 " FW HM angular resolution, these radio and optical limits include nearly all LC RS galaxies with 1.4 GHz luminosities L greater than or equal to 10(22.4) W Hz(-1) at z approximate to 0.05 to L greater than or equal to 10(23.6) W H z(-1) at z approximate to 0.2. The mean redshift [z] approximate to 0.14 of the radio-detected galaxies is higher than the mean redshift [z] approxima te to 0.10 of the optical sample. This indicates that, statistically, the r adio emission was detected from galaxies with the highest optical luminosit ies. Of the 1157 galaxies, 261 were also identified with far-infrared (FIR) sources in the IRAS Point Source Catalog and Faint Source Catalog. The pri ncipal radio energy sources in all identified galaxies were classified as e ither "starburst" or "AGN" on the basis of their FIR-radio flux ratios, FIR spectral indices, and radio-optical flux ratios. We show that the radio-op tical flux ratio can be effectively used to classify the dominant energy so urce for the radio emission even if FIR fluxes and radio morphological data are not available.