Related papers: High redshift FRII radio sources: large-scale X-ra…

We have quantified the galaxy environments around a sample of 0.5 < z < 0.8 radio-quiet quasars using the amplitude of the spatial galaxy--quasar correlation function, B_gq. The quasars exist in a wide variety of environments, some sources…

We search for high redshift ($z\sim$1-2) galaxy clusters using low luminosity radio galaxies (FR~I) as beacons and our newly developed Poisson Probability Method (PPM) based on photometric redshift information and galaxy number counts. We…

We aim to study the effect of environment on the presence and fuelling of Active Galactic Nuclei (AGN) in massive galaxy clusters. We explore the use of different AGN detection techniques with the goal of selecting AGN across a broad range…

Evidence for non-thermal activity in clusters of galaxies is well established from radio observations of synchrotron emission by relativistic electrons. New windows in the Extreme Ultraviolet and Hard X-ray ranges have provided for more…

The environments of a complete subsample of 6 of the most powerful radio-loud AGN at redshifts z~1.6 are investigated, using deep RJK imaging to depths of R~26, J~22.4 and K~20.6. An excess of galaxy counts in the K-band is seen across…

We present a statistical study of the environments of 63 high-redshift radio galaxies (HzRGs) between redshifts 1<z<5.2, using the 24um, waveband of the MIPS instrument aboard the Spitzer Space Telescope. Using a counts-in-cell analysis, a…

From ROSAT imaging data we have detections and upper limits for a sample of 26 tailed radio sources in clusters of galaxies mostly from the sample of O'Dea \& Owen (1985). All sixteen of the detected sources are unresolved in the ROSAT PSPC…

We are conducting a large survey of distant clusters of galaxies using radio sources with bent jets and lobes as tracers. These radio sources are driven by AGN and achieve their bent morphologies through interaction with the surrounding gas…

The environment of the high-redshift (z=1.408), powerful radio-loud galaxy 3C 297 has several distinctive features of a galaxy cluster. Among them, a characteristic halo of hot gas revealed by Chandra X-ray observations. In addition, a…

We show that the most distant X-ray detected cluster known to date, ClJ1001 at z=2.506, hosts a strong overdensity of radio sources. Six of them are individually detected (within 10") in deep 0.75" resolution VLA 3GHz imaging, with…

We have obtained near-infrared (1.6 micron) images of 11 powerful 3CR radio galaxies at redshifts 0.8 < z < 1.8 using NICMOS on board HST. The high angular resolution permits a detailed study of galaxy morphology in these systems at…

By cross-correlating the 1.4 GHz FIRST catalog of radio sources with the Abell cluster catalog we have found an excess surface density by a factor ~5 of radio sources within a projected distance, r_p, of 0.1 Mpc (for h=0.65) from the…

Many of the most luminous extragalactic radio sources are located at the centers of X-ray clusters, and so their radiation must be scattered by the surrounding hot gas. We show that radio observations of the highly-polarized scattered…

The most spectacular aspect of cluster radio emission is represented by the large-scale diffuse radio sources, which cannot be obviously associated with any individual galaxy. These sources demonstrate the existence of relativistic…

We explore the implications of our optical spectroscopic survey of 3CR radio sources with z<0.3 for the unified model (UM) for radio-loud AGN, focusing on objects with a FRII radio morphology. The sample contains 33 high ionization galaxies…

We present a detailed analysis of 256 radio sources from our deep (flux density limit of 42 microJy at the field centre at 1.4 GHz) Chandra Deep Field South 1.4 and 5 GHz VLA survey. The radio population is studied by using a wealth of…

We perform a stacking analysis of H-ATLAS data in order to obtain isothermal dust temperatures and rest-frame luminosities at 250um (L250), for 1599 radio sources over the H-ATLAS P1 GAMA area. The radio sample is generated using a…

We select a sample of radio galaxies at high redshifts (z>~1) in the COSMOS field, by cross-matching optical/infrared images with the FIRST radio data. The aim of this study is to explore the high-z radio-loud (RL) AGN population at much…

Since radio sources with Ultra Steep Spectra (USS; alpha <~ -1.30; S ~ nu^alpha) are efficient tracers of high redshift radio galaxies (HzRGs), we have defined three samples of such USS sources using the recently completed WENSS, TEXAS,…

We investigate the radio properties of a complete sample of nearby, massive, X-ray bright elliptical and S0 galaxies. Our sample contains 18 galaxies with ROSAT All-Sky Survey X-ray fluxes Fx_(0.1-2.4 keV) > 3 x 10^(-12) erg/s/cm^2, within…