High redshift radio galaxies from the Molonglo Catalogue. II

Abstract

We report further results from the ongoing study of radio galaxies from the Molonglo Reference Catalogue are reported. The sources were selected to have 408 MHz flux densities greater than 0.95 Jy and low frequency spectral indices steeper than -0.9. VLA 6-cm maps, optical identifications and redshifts for 18 sources are presented. Most of these sources are identified with faint galaxies, many of which have extended optical structures with morphologies characteristic of high redshift (z greater than 1) radio galaxies. Long slit spectroscopic observations have yielded redshifts for all of the galaxies, three of which have z greater than 2. Spectrophotometry of 1 Jy and the 3CR samples are used to distinguish between an L (emission line) versus L (radio) correlation as opposed to an L (emission line) versus redshift correlation. The results strongly support an intrinsic L (emission line) versus L (radio) correlation. The structures of the sources in this and other 1 Jy samples are substantially different fro the 3C sources, the 1 Jy galaxies having stronger cores and jets.