Related papers: Radio-loudness along the quasar main sequence
We have conducted 22 GHz radio imaging at 1" resolution of 100 low-redshift AGN selected at 14-195 keV by the Swift-BAT. We find a radio core detection fraction of 96%, much higher than lower-frequency radio surveys. Of the 96…
The radio luminosity function (RLF) of radio galaxies and radio-loud quasars is often modelled as a broken power-law. The break luminosity is close to the dividing line between the two Fanaroff-Riley (FR) morphological classes for the…
Remnant radio galaxies (RRGs), characterized by the cessation of AGN activity, represent a short-lived last phase of radio galaxy's life-cycle. Hitherto, searches for RRGs, mainly based on the morphological criteria, have identified large…
We have observed the galaxy environments around a sample of 21 radio-loud, steep-spectrum quasars at 0.5<z<0.82, spanning several orders of magnitude in radio luminosity. The observations also include background control fields used to…
We present 6 GHz e-MERLIN observations of 42 $z<0.2$ type 1 and type 2 mostly radio-quiet quasars ($L_{\rm[OIII]}\gtrsim10^{42}$ erg s$^{-1}$; $L_{\rm AGN}\gtrsim10^{45}$ erg s$^{-1}$) from the Quasar Feedback Survey. The nature and origin…
AGN feedback now appears as an attractive mechanism to resolve some of the outstanding problems with the "standard" cosmological models, in particular those related to massive galaxies. To directly constrain how this may influence the…
The role of radio mode feedback in non radio-loud quasars needs to be explored in depth to determine its true importance. Its effects can be identified based on the evidence of interactions between the radio structures and the ambient…
We constrain the behavior of the radio luminosity function (RLF) of two classes of active galactic nuclei (AGN) namely AGN of low radio power (LRP) and BL Lac objects. The extrapolation of the observed steep RLFs to low power predicts a…
To understand the Active Galactic Nuclei (AGN) phenomenon and their impact on the evolution of galaxies, a complete AGN census is required; however, finding heavily obscured AGNs is observationally challenging. Here we use the deep and…
We have studied the host galaxies of a sample of radio-loud AGN spanning more than four decades in the energy output of the nucleus. The core sample includes 40 low-power sources (BL Lac objects) and 22 high-power sources (radio-loud…
We use highly spectroscopically complete observations of the radio sources from the VLA 1.4 GHz survey of the HDF-N region to study the faint radio galaxy population and its evolution. We spectrally classify the sources into four spectral…
There has been a growing body of evidence to suggest that AGN activity, which is powered by mass accretion on to a supermasive black hole, could be episodic, although the range of time scales involved needs to be explored further. The…
In order to determine the incidence of black hole accretion-driven nuclear activity in nearby galaxies, as manifested by their radio emission, we have carried out a high-resolution Multi-Element Radio-Linked Interferometer Network (MERLIN)…
We have used Kepler photometry to characterize variability in four radio-loud active galactic nuclei (three quasars and one object tentatively identified as a Seyfert 1.5 galaxy) on timescales from minutes to months, comparable to the light…
We investigate the properties and the environment of radio sources with optical counterpart from the combined VLA-COSMOS and zCOSMOS samples. The advantage of this sample is the availability of optical spectroscopic information, high…
Occupying the intermediate-mass regime of the accretion--jet parameter space, radio continuum emission from active galactic nuclei with black hole mass M_BH <~ 10^6 Msun (low-mass AGNs) is a valuable probe to the physics of relativistic…
Despite targets of many multiwavelength campaigns, the main physical processes at work in AGN are still under debate. In particular the origin of the radio emission and the mechanisms involved are among the open questions in astrophysics.…
A catalogue of 14453 radio-loud AGN with 1.4 GHz fluxes above 3.5 mJy in the redshift range 0.4<z<0.8, has been constructed from the cross-correlation of the NVSS and FIRST radio surveys with the MegaZ-LRG catalogue of luminous red galaxies…
A 10-arcmin field around the HDF(N) contains 92 radio sources >40 uJy, resolved by MERLIN+VLA at 0".2-2".0 resolution. 55 have Chandra X-ray counterparts including 18 with a hard X-ray photon index and high luminosity characteristic of a…
Starting from a complete sample of type I AGN observed by INTEGRAL in the 20-40 keV band, we have selected a set of 8 AGN which can be classified as radio loud objects according to their 1.4 GHz power density, radio to hard X-ray flux flux…