Ultra--Steep-Spectrum Radio Sources. I. 4C Objects

Abstract
We present radio total intensity and polarization images and complete optical identifications of a representative sample of ultra-steep-spectrum 4C objects. The radio morphologies are all resolved into double lobes or triples with cores. The radio polarization intensity morphologies are strikingly asymmetric. The optical identifications consist of galaxies in distant clusters (0.4 < z < 1.0), quasars, and high-redshift (z > 1) radio galaxies. We identify several (1 < z < 2) cluster candidates, and faint candidates for very high redshift radio galaxies.