We report the discovery of a new radio galaxy within the location error box of the γ-ray source 3EG J1735−1500. The galaxy is a double-sided jet source forming a large angle with the line of sight. Optical observations reveal a V ∼ 18 magnitude galaxy at the position of the radio core. Although the association with the EGRET source is not confirmed at the present stage, because there is a compe...

The advent of sensitive polarimeters on large telescopes has led to a revolution in our understanding of active galaxies over the last 20 years. In the case of powerful radio galaxies the deep polarimetric measurements made possible by the new technology have: (a) provided the most direct evidence to support the unified schemes for powerful radio galaxies; (b) enhanced our understanding of the ...

We present a comparison between the published optical, IR and CO spectroscopic redshifts of 15 (sub-)mm galaxies and their photometric redshifts as derived from longwavelength (radio–mm–FIR) photometric data. The redshift accuracy measured for 12 sub-mm galaxies with at least one robustly-determined colour in the radio–mm–FIR regime is δz ≈ 0.30 (r.m.s.). Despite the wide range of spectral ener...

We report on ROSAT HRI observations of the z = 0.61 radio galaxy 3C 220.1. The X-ray emission from this object consists of an extended component, which we attribute to luminous cluster emission, and a compact central source. The compact component is too bright to be modelled as a cooling flow under some plausible assumptions for the hot gas temperature and distribution; we suggest instead that ...

The distribution of luminous radio galaxies in galaxy clusters has been observed to be concentrated in the inner region. We consider the role of dynamical friction of massive galaxies (M ∼ 10 M⊙), assuming them to be hosts of luminous radio galaxies, and show that beginning with a Navarro-Frenk-White density profile of a cluster of mass Mcl ∼ 10 15 M⊙ of concentration c ∼ 5 and collapsing at z ...

Historically, Seyfert nuclei have been considered to be radio-quiet active galactic nuclei (AGNs). We question this widely held assumption by showing that the distribution of the radio-to-optical luminosity ratio, R ≡ Lν(6 cm)/Lν(B), when properly measured for the nuclear component, places the majority of type 1 Seyfert nuclei in the category of radio-loud AGNs, defined here as objects with R ≥...

A systematic search for 22 GHz H2O megamaser emission is reported for 50 nearby (z <∼ 0.15) FR I galaxies. No detection was obtained, implying that ultraluminous H2O masers (LH2O > 10 3 L ) must be rare in early-type galaxies with FR I radio morphology. Despite higher radio core luminosities the detection rate for our sample is lower than in similar surveys of late-type Seyfert galaxies. This p...

We have obtained the first constraints on extended Lyα emission at z ∼ 1 in a sample of five radio galaxies. We detect Lyα emission from four of the five galaxies. The Lyα luminosities range from 0.1−4×10 erg s and are much smaller than those observed for halos around higher redshift radio galaxies. If the z ≈ 1 radio galaxies are the descendents the z ∼ > 2 radio galaxies, then their Lyα lumin...

We report on a statistical study of the 51 radio galaxies at the millijansky flux level from the Faint Images of the Radio Sky at Twenty centimeters, including their optical morphologies and structure obtained with the Hubble Space Telescope. Our optical imaging is significantly deeper (∼2 mag) than previous studies with the superior angular resolution of space-based imaging. We that find 8/51 ...

We define a sample of 27 radio-excess AGN in the Chandra Deep Field North by selecting galaxies that do not obey the radio/infrared correlation for radio-quiet AGN and star-forming galaxies. Approximately 60% of these radio-excess AGN are X-ray undetected in the 2 Ms Chandra catalog, even at exposures of ≥ 1 Ms; 25% lack even 2σ X-ray detections. The absorbing columns to the faint X-ray-detecte...