We analyze the optical spectra of massive (log M∗/M⊙ > 11.4) radio-loud galaxies at z ∼ 0.2 and z ∼ 0.6. Our samples are generated by crossmatching the SDSS DR7 and BOSS spectroscopic galaxy catalogues with the FIRST and NVSS radio continuum surveys. By comparing stellar population parameters of these radio-loud samples with radio-quiet control samples matched in stellar mass, velocity dispersi...

We present optical spectroscopic observations of 93 galaxies taken from the infra-red selected COLA (Compact Objects in Low Power AGN) sample. These are all galaxies for which we have previously obtained low resolution radio observations and high resolution (< 0.05′′) Long Baseline Array (LBA) snapshots. The sample spans the range of far-IR luminosities from normal galaxies to LIRGs, and contai...

We present evidence that the 3CR radio galaxies at redshift z ∼ 1 are already very massive, highly dynamically evolved galaxies, which lie at the heart of (proto–)cluster environments. Since nearby 3CR double radio sources are generally found in more isolated surroundings, the galactic environments of these galaxies must change dramatically with redshift. Therefore, the original ‘uniform popula...

The parsec scale properties of low power radio galaxies are reviewed here, using the available data on 12 FR I galaxies. The most frequent radio structure is an asymmetric parsec-scale morphology, i.e. core and one-sided jet. It is shared by 9 (possibly 10) of the 12 mapped radio galaxies. One (possibly 2) of the other galaxies has (have) a two-sided jet emission. Two sources are known from pub...

HST observations have shown that low-redshift 3CR radio galaxies often exhibit a point-like optical component positionally coincident with the GHz-frequency radio core. In this paper we discuss the correlation between the luminosities of the radio, optical and X-ray cores in these objects, and argue that all three components have a common origin at the base of the relativistic jets. In unified ...

Deep VLA 1.4 GHz radio continuum imaging of Abell 2255 is presented. This cluster is among the better nearby candidates for rich cluster-cluster merger systems, with evidence including an elongated X-ray morphology, the presence of a radio halo, and substructure present in its galaxy distribution. Our radio observations reach an rms sensitivity of ∼ 40μJy beam, enabling us to detect (at 5σ) sta...

Giant radio galaxies (GRGs) are the largest structures associated with single galaxies. Their linear sizes exceed 1 Mpc and so they form the extreme tail of the radio galaxy population. Because they have expanded to such large sizes, GRGs are thought to be the endpoint of radio galaxy evolution and provide important constraints to evolutionary models. They extend well past the environment of th...

We have obtained U-band polarimetry of the spatially extended, blue optical continuum associated with the FR I radio source PKS 2322−122. PKS 2322−122 is located in the Abell 2597 cluster central galaxy. We find a three sigma upper limit to the degree of polarization of the optical continuum of less than 6%. The accuracy of the measurement is limited primarily by our ability to measure the amou...

We cross-correlate the galaxies brighter than mB = 18 in the Virgo cluster with the radio sources in the NVSS survey (1.4 GHz), resulting in 180 radio-optical identifications. We determine the radio luminosity function of the Virgo galaxies, separately for the earlyand late-types. Late-type galaxies develop radio sources with a probability proportional to their optical luminosity. In fact their...

We cross-correlate the galaxies brighter than mB = 18 in the Virgo cluster with the radio sources in the NVSS survey (1.4 GHz), resulting in 180 radio-optical identifications. We determine the radio luminosity function of the Virgo galaxies, separately for the earlyand late-types. Late-type galaxies develop radio sources with a probability proportional to their optical luminosity. In fact their...