Related papers: Evidence for radio loud to radio quiet evolution f…
We present quasi-simultaneous multi-colour optical/near-IR photometry for 157 radio selected quasars, forming an unbiassed sub-sample of the Parkes Flat-Spectrum Sample. Data are also presented for 12 optically selected QSOs, drawn from the…
GPS and CSS radio sources are the objects of choice to investigate the evolution of young radio-loud AGN. Previous investigations, mainly based on number counts and source size distributions, indicate that GPS/CSS sources decrease…
We present the evolution of the phase lags associated with the type-C QPO in GX 339--4 during the rising phase of the 2006/2007 outburst. We find that the phase lags at the QPO frequency are always positive (hard), and show very different…
A database of radio-quiet quasars detected with ROSAT is presented containing 846 quasars seen in the All-Sky Survey and/or in pointed PSPC observations. About 70% of the objects have been detected in X-rays for the first time. We present…
In classifying the ensemble of powerful extragalactic radio sources, considerable evidence has accumulated that radio galaxies and quasars are orientation-dependent manifestations of the same parent population: massive spheroidal galaxies…
Broad Absorption Line Quasars (BALQSOs) show strong signatures of powerful outflows, with the potential to alter the cosmic history of their host galaxies. These signatures are only seen in ~10% of optically selected quasars, although the…
Quasars are generally divided into jetted radio-loud and non-jetted radio-quiet ones, but why only 10% quasars are radio loud has been puzzling for decades. Other than jet-induced-phenomena, black hole mass, or Eddington ratio, prominent…
Current wide-area radio surveys are dominated by active galactic nuclei, yet many of these sources have no identified optical counterparts. Here we investigate whether one can constrain the nature and properties of these sources, using…
The observed two-point angular correlation function, w(theta), of mJy radio sources exhibits the puzzling feature of a power-law behaviour up to very large (almost 10 degrees) angular scales which cannot be accounted for in the standard…
Recent studies of black holes in the nuclei of both active and normal galaxies have yielded relationships that permit a physical interpretation of the principal components of the spectra of QSOs. It is shown that principal component (or…
The results of a comprehensive study of the cluster environments and black-hole masses of an optically matched sample of radio-loud and radio-quiet quasars are presented. No evidence is found for a difference in large-scale environments,…
Broad absorption lines (BALs) are present in the spectra of ~20% of quasars (QSOs); this indicates fast outflows (up to 0.2c) that intercept the observer's line of sight. These QSOs can be distinguished again into radio-loud (RL) BAL QSOs…
We present an analysis of X-ray variability in a sample of 156 radio quiet quasars taken from the ROSAT archive, covering a redshift range 0.1 < z < 4.1. A maximum likelihood method is used to constrain the amplitude of variability in these…
We present spectroscopic and eleven-band photometric redshifts for galaxies in the 100-uJy Subaru/XMM-Newton Deep Field radio source sample. We find good agreement between our redshift distribution and that predicted by the SKA Simulated…
Recent investigations of how the median size of extragalactic radio sources change with redshift have produced inconsistent results. Eales compared the radio and optical properties of a bright 3C and faint 6C sample and concluded that…
We present the results of a study which uses the 3CRR sample of radio-loud active galactic nuclei to investigate the evolution of the black-hole:spheroid mass ratio in the most massive early-type galaxies from 0<z<2. Radio-loud unification…
The evolution of the comoving kinetic luminosity densities ($\Omega_{\rm{kin}}$) of the radio loud (RL) high-excitation radio galaxies (RL HERGs) and the low-excitation radio galaxies (LERGs) in the XXL-S field is presented. The wide area…
In the now well established conventional view (see Rees [1] and references therein), quasi-stellar objects (QSOs) and related active galactic nuclei (AGN) phenomena are explained as the result of accretion of plasma onto giant black holes…
Using a sample of optically-selected quasars from the Sloan Digital Sky Survey, we have determined the radio-loud fraction (RLF) of quasars as a function of redshift and optical luminosity. The sample contains more than 30,000 objects and…
Investigating the assembly history of the most massive and passive galaxies will enhance our understanding of why galaxies exhibit such a remarkable diversity in structure and morphology. In this paper, we simultaneously investigate the…