Hubble Space Telescope imaging of compact steep spectrum radio sources

We present Hubble Space Telescope WFPC2 images taken through a broad red filter (F702W) of 30 Third Cambridge Catalog compact steep spectrum (CSS) radio sources. We have overlaid radio maps taken from the literature on the optical images to determine the radio-optical alignment and to study detailed correspondence. All CSS sources for which the relative orientation between the optical and radio can be measured display good alignment between the optical and radio emission down to the lowest redshift in the sample, z similar to 0.1. The alignment effect does not occur at this relatively low redshift for the large-scale 3CR radio sources, which tend to show a significant alignment only at z > 0.6, as shown by McCarthy et al., Chambers et al., and de Koff et al. We find candidates for optical synchrotron hot spots in 3C 213.1 and 3C 380 and an optical jet in 3C 346.