Related papers: Distant Radio Galaxies and their Environments
Clusters of galaxies, as the largest virialized systems in the Universe, are ideal laboratories to study the formation and evolution of cosmic structures...(abridged)... Most of the detailed knowledge of galaxy clusters has been obtained in…
We present an analysis of a large sample of AGN environments at z~1 using stacked Spitzer data at 3.6um. The sample contains type-1 and type-2 AGN in the form of quasars and radio galaxies, and spans a large range in both optical and radio…
Luminous infrared galaxies are systems enshrouded in dust, which absorbs most of their optical/UV emission and re-radiates it in the mid- and far-infrared. Radio observations are largely unaffected by dust obscuration, enabling us to study…
We present the results of a comparison between the optical morphologies of a complete sample of 46 southern 2Jy radio galaxies at intermediate redshifts (0.05<z<0.7) and those of two control samples of quiescent early-type galaxies: 55…
We present a high spatial-resolution HST/NICMOS imaging survey in the field of a known protocluster surrounding the powerful radio galaxy MRC1138-262 at z=2.16. Previously, we have shown that this field exhibits a substantial surface…
Previously it has been recognized that radio halos in galaxy clusters are preferentially associated with merging systems as indicated by substructure in the X-ray images and temperature maps. Since, however, many clusters without radio…
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…
We present the K-band Hubble diagrams (K-z relations) of sub-mm-selected galaxies and hyperluminous galaxies (HLIRGs). We report the discovery of a remarkably tight K-z relation of HLIRGs, indistinguishable from that of the most luminous…
We present results from a comprehensive imaging survey of 70 radio galaxies at redshifts 1<z<5.2 using all three cameras onboard the Spitzer Space Telescope. The resulting spectral energy distributions unambiguously show a stellar…
CO observations of 0<z<4 radio galaxies are presented. The L_CO upper limits for the high-redshift powerful radio galaxies (HzPRGs: z > 1, P_408MHz > 10^27 Watts/Hz) are consistent with no evolution in molecular gas (H_2) mass with redshift…
Using radio data at 1.4 GHz from the ATCA we identify five head-tail (HT) galaxies in the central region of the Horologium-Reticulum Supercluster (HRS). Physical parameters of the HT galaxies were determined along with substructure in the…
We investigate the kinematic properties of a large (N=998) sample of COSMOS spectroscopic galaxy members distributed among 79 groups. We identify the Brightest Group Galaxies (BGGs) and cross-match our data with the VLA-COSMOS Deep survey…
Deep and high resolution radio observations of the Hubble Deep Field and flanking fields have shown the presence of two distant edge-darkened FR I radio galaxies, allowing for the first time an estimate of their high redshift space density.…
(Abridged) We have used optical spectroscopy to investigate the radio- selected active galaxy populations in a sample of 20 nearby Abell clusters. The spectra were used to characterize the galaxies as AGN or galaxies forming stars at rates…
The host galaxies of powerful radio sources are ideal laboratories to study active galactic nuclei (AGN). The galaxies themselves are among the most massive systems in the universe, and are believed to harbor supermassive black holes…
How and when do galaxies form? Studies of the microwave background radiation reveal that the Universe is spectacularly homogenous at redshift z~1000. Observations of the local Universe reveal that by z=0 much of the luminous matter has…
(Abridged) We report on the properties of radio-selected galaxies within 30 very-rich Abell clusters with z < 0.25. These radio data sample the ultra-faint (L(1.4) > 2E22 W/Hz) radio galaxy population with M_R < -21 using the well-known…
Non-thermal properties of galaxy clusters have been studied with detailed and deep radio images in comparison with X-ray data. While much progress has been made, most of the studied clusters are at a relatively low redshift (z < 0.3). We…
An analysis of the cluster environments around distant radio galaxies is presented, in particular the results from new NTT deep optical-IR imaging of the fields of radio sources at z ~ 1.6. A net overdensity of K-band galaxies is found,…
Radio Galaxies have by now emerged as a new $\gamma$-ray emitting source class on the extragalactic sky. Given their remarkable observed characteristics, such as unusual gamma-ray spectra or ultrafast VHE variability, they represent unique…