Related papers: Radio-quiet objects in the 2QZ survey
We present a technique to explore the radio sky into the nanoJansky regime by employing image stacking using the FIRST survey. We first discuss the non-intuitive relationship between the mean and median values of a distribution that is…
For some samples, it has been shown that spectra of QSOs with low redshift are bluer during their brighter phases. For the FIRST bright QSO sample, we assemble their spectra from SDSS DR7 to investigate variability between the spectra from…
We present optical spectroscopy, near-infrared (mostly K-band) and radio (151-MHz and 1.4-GHz) imaging of the first complete region (TOOT00) of the TexOx-1000 (TOOT) redshift survey of radio sources. The 0.0015-sr (~ 5 deg^2) TOOT00 region…
In this paper, the availability of multi-wavelength optical/infrared information of FIRST (Faint Images of the Radio Sky at 20 cm) radio sources counterparts over ~9.2 deg^{2} in Bootes field and ~2.4 deg^{2} in Cetus field is exploited to…
We present clustering results from the 2dF QSO Redshift Survey (2QZ) which currently contains over 20,000 QSOs at z<3. The two-point correlation function of QSOs averaged over the entire survey (<z>~1.5) is found to be similar to that of…
The recent detection of the quasi-stellar object (QSO) VIKING J231818.3$-$311346 (hereafter VIK J2318$-$3113) at redshift $z=6.44$ in the Rapid ASKAP Continuum Survey (RACS) uncovered its radio-loud nature, making it one of the most distant…
We match quasars discovered in a multi-color survey centered on the northern Hubble Deep Field (HDF) with radio sources from an ultra-deep radio survey. Although 3 out of 12 quasars are detected at a level below 0.2 mJy at 1.4 GHz, all of…
The completed 2dF QSO Redshift (2QZ) Survey has been used to search for extreme large-scale cosmological structure (around 200 Mpc) over the redshift range 0<z<2.5. We demonstrate that statistically significant overdensities and…
We present the method and first results of a survey for high-redshift (z>3) radio-loud quasars, which is based on optical identifications of 2902 flat-spectrum radio sources with S(5GHz)>= 25mJy. The radio sample was defined over a 1600 sq…
We report the discovery of a radio-loud flat-spectrum QSO at z=5.47 with properties similar to those of the EGRET gamma-ray blazars. This source is the brightest radio QSO at z>5, with a pc-scale radio jet and a black hole mass estimate…
Despite decades of study, it remains unclear whether there are distinct radio-loud and radio-quiet populations of quasi-stellar objects (QSOs). Early studies were limited by inhomogeneous QSO samples, inadequate sensitivity to probe the…
Spectroscopic observations of a sample of 42 flat-spectrum radio sources from the Cosmic Lens All-Sky Survey (CLASS) have yielded a mean redshift of $<z> = 1.27$ with an RMS spread of 0.95, at a completeness level of 64%. The sample…
We present multi-frequency radio observations of a sample of z~2 obscured (type-2) quasars in the Spitzer extragalactic First Look Survey area. We combine the public data at 1.4 GHz, used in the selection of these sources, with new…
We present Very Large Array (VLA) observations at 1.4 GHz and 5 GHz of a sample of 12 Quasi-stellar Objects (QSOs) at z = 3.99 to 4.46. The sources were selected as the brightest sources at 250 GHz from the recent survey of Omont et al.…
Using the SPITZER SPACE TELESCOPE and the VLA, we present the first DIRECT evidence that the well-known far-infrared/radio correlation is valid to cosmologically significant redshift. We also confirm, with improved statistics compared with…
We present a clustering analysis of QSOs using over 20000 objects from the final catalogue of the 2dF QSO Redshift Survey (2QZ), measuring the z-space correlation function, xi(s). When averaged over the range 0.3<z<2.2 we find that xi(s) is…
We present spectroscopic observations obtained with the ESO Very Large Telecope (VLT) of seven candidate Ly-alpha emitting galaxies in the field of the radio quiet Q1205-30 at z=3.04 previously detected with deep narrow band imaging. Based…
The TexOx-1000 (TOOT) radio source redshift survey is designed to find and study typical radio-loud active galaxies to high redshift. They are typical in the same sense that L* galaxies are typical of galaxies in the optical. Previous…
We present the final catalogue of the 2dF QSO Redshift Survey (2QZ), based on Anglo-Australian Telescope 2dF spectroscopic observations of 44576 colour-selected (u b_J r) objects with 18.25<b_J<20.85 selected from APM scans of UK Schmidt…
We report a measurement of the quadrupole power spectrum in the two degree field (2dF) QSO redshift (2QZ) survey. The analysis uses an algorithm parallel to that for the estimation of the standard monopole power spectrum without first…