The results of analysis of HST I−band imaging of a sample of 41 radio galaxies spanning three orders of magnitude in radio luminosity at redshift z ≃ 0.5 are presented. These results represent the first stage in a coordinated programme to study the connection between radio luminosity and host-galaxy properties, black-hole masses and cluster environments in radio galaxies spanning a wide range i...

We quantify the angular distribution of radio sources in the NVSS by measuring the two-point angular correlation function w(θ). By careful consideration of the resolution of radio galaxies into multiple components, we are able to determine both the galaxy angular clustering and the size distribution of giant radio galaxies. The slope of the correlation function for radio galaxies agrees with th...

We have used optical spectroscopy to investigate the active galaxy populations in a sample of 20 nearby Abell clusters. The targets were identified on the basis of 1.4 GHz radio emission, which identifies them as either AGN or galaxies forming stars at rates comparable to or greater than that of the Milky Way. The spectra were used to characterize the galaxies via their emission and absorption ...

We present K-band imaging of all 49 radio galaxies in the 7C–I and 7C–II regions of the 7C Redshift Survey (7CRS). The low–frequency (151 MHz) selected 7CRS sample contains all sources with flux-densities S151 > 0.5 Jy in three regions of the sky. We combine the K-band magnitudes of the 7CRS radio galaxies with those from the 3CRR, 6CE and 6C⋆ samples to investigate the nature of the relationsh...

We present morphological and photometric properties of 79 low redshift (z ≤ 0.12) radio galaxies extracted from two radio flux limited samples of radio sources. All objects are imaged in the R band and for a subsample we have also obtained B band images. The sample includes sources of both FRI and FRII radio morphological type. Through the decomposition of the luminosity profiles and the analys...

A search for H I absorption has been made in 23 radio galaxies selected from a complete sample. The observations were made with the Australia Telescope Compact Array (ATCA), with the Very Large Array (VLA) and for one galaxy with the Westerbork Synthesis Radio Telescope (WSRT). In five galaxies H I absorption was detected. We investigate how the detection rate is distributed among galaxies with...

We present an optical spectroscopic and imaging study of the environments of a complete sample of moderate-redshift, bent-double radio sources. More than half of the forty radio galaxies in the sample are associated with Abell richness class 0 or greater clusters at z < 0.4. Most of the remaining objects are associated with groups, although a few appear to be hosted by nearly isolated elliptica...

We present near-infrared J and K band imaging of a sample of powerful radio source host galaxies with the Hubble Space Telescope NICMOS2 camera. These sources have been selected on their double lobed radio structure, and include a wide range of projected radio source sizes. The largest projected linear sizes range from the compact Gigahertz Peaked Spectrum (GPS, < 1 kpc) and Compact Steep Spect...

We investigate the radio emission of ∼ 185,000 quiescent (optically unclassifiable) galaxies selected from the Sloan Digital Sky Survey (SDSS). By median-stacking FIRST cutouts centered on the optically-selected sources, we are able to reach flux densities down to the 10s of μJy. The quiescent galaxy sample is composed of two subgroups inhabiting vastly different regimes: those targeted for the...