Following Minkowski's footsteps: a survey of distant radio sources.

The current status of optical identifications of 3CR radio sources is reported, and ongoing work on spectroscopy of faint radio galaxies is described. By now, about 64% of the 3CR sources have been securely identified. Statistics for those identified, which are distributed over a large range of apparent radio flux density and a large range of redshift and apparent optical magnitude, are presented. The optical luminosities of the radio galaxies are all near the top of the E cluster-galaxy sample, with Mv roughly -23.5 and Hubble constant of 50 km/sec Mpc. The spectroscopic research on faint radio galaxies has the goals of determination of redshift, measuring the galaxy continuum color and checking possible galaxy color evolution with z, and studying emission lines for insight into physics of the ionized gas near the excited source. Research has shown that for V above 19, radio galaxies of any intrinsic power generally have weak emission, with forbidden O II at 3727 A being the most common. The problems this causes in redshift determination are discussed.