Ultra--Steep-Spectrum Radio Sources. II. Radio, Infrared, Optical, and HST Imaging of High-Redshift 4C Objects

Abstract

We present radio, infrared, optical, and HST imaging data on eight high-redshift (z > 2) ultra-steep-spectrum 4C radio sources. The radio polarization morphologies are highly asymmetric, indicating large rotation measures across the objects. The optical morphologies are all aligned with the radio axis. The multicolor images show strong asymmetric gradients in the color of the continuum along the radio axes. No optical emission is detected from the radio lobes. Narrowband images of the redshifted Lyα emission show that the emission-line morphology is generally aligned with the radio source but does not necessarily correspond to the apparent morphology of the rest-frame ultraviolet continuum.