We present deep, ≈ 1.6μm, continuum images of eleven high-redshift (0.811 < z < 1.875) 3CR radio galaxies observed with NICMOS on-board the Hubble Space Telescope. Our NICMOS images probe the rest-frame optical light where stars are expected to dominate the galaxy luminosity. The rest-frame ultraviolet light of eight of these galaxies demonstrates the well-known “alignment effect”, with extende...

Low luminosity “FRI” radio galaxies constitute by far the largest population of radio loud AGN in the local universe. They are invariably associated with the most massive elliptical galaxies, they are likely to possess supermassive black holes of 10 solar masses and higher and, differently for the more powerful “FRIIs”, they reside in rich clusters of galaxies. Therefore, they can be used as “b...

The Australia Telescope Compact Array (ATCA) has been used at 1.38 and 2.38 GHz to survey seven southern Abell clusters of galaxies with high X-ray luminosities: A2746, A2837, A3126, A3216, A3230, A3827 and A3836. The clusters have also been surveyed at 0.843 GHz with the Molonglo Observatory Synthesis Telescope (MOST). We have listed a complete 1.38GHz sample of 149 radio sources within the Ab...

The results of Chandra snapshot observations of 11 LINERs (Low-Ionization Nuclear Emission-line Regions), three low-luminosity Seyfert galaxies, and one H II-LINER transition object are presented. Our sample consists of all the objects with a flat or inverted spectrum compact radio core in the VLA survey of 48 low-luminosity AGNs (LLAGNs) by Nagar et al. (2000). An X-ray nucleus is detected in ...

The prevalence of radio-loud AGN activity in present-day massive halos is determined using a sample of 625 nearby groups and clusters selected from the Sloan Digital Sky Survey. Brightest group and cluster galaxies (BCGs) are more likely to host a radio– loud AGN than other galaxies of the same stellar mass (by below a factor of two at a stellar mass of ∼ 5 × 1011M⊙, but rising to over an order...

Aims. In order to analyze the importance of the star formation rate in generating and amplifying magnetic fields in the interstellar medium we perform a deep continuum polarization study of three angularly large, late type spiral galaxies. Methods. We obtained deep total power and polarization maps at 4.85 GHz of NGC 4236, NGC 4656 and IC 2574 using the 100-m Effelsberg radio telescope. This wa...

To constrain models of the jet–disc connection, we explore Eddington ratios reported in Foschini (2011) and interpret them in relation to the values in Sikora et al. across the active galactic nuclei population from radio loud quasars, their flat spectrum radio quasar subclass, the recently discovered gamma-ray loud narrow-line type 1 Seyfert galaxies, Fanaroff–Riley type I (FR I) radio galaxie...

Recent results on the radio emission from galaxy clusters are reviewed, with emphasis both on the radio galaxies and on the diffuse radio emission from the intracluster medium. We show that the formation of the tailed morphology in cluster radio galaxies is due to the effect of the cluster gaseous environment and of its large scale motions in merging clusters. From Chandra X-ray data, it has al...

We report the detection of a diffuse radio halo source in the hottest known cluster of galaxies 1E0657−56 (RXJ0658−5557). The radio halo has a morphology similar to the X-ray emission from the hot intracluster medium. The presence of a luminous radio halo in such a hot cluster is further evidence for a steep correlation between the radio halo power and the X-ray temperature. We favour models fo...

We present in this paper a detailed study of a new sample of large angular size FR I and FR II radio galaxies and compare the properties of the two classes. As expected, a pure morphology based distinction of FR Is and FR IIs corresponds to a break in total radio power. The radio cores in FR Is are also weaker than in FR IIs, although there is not a well defined break power. We find that asymme...