Related papers: A multi-wavelength continuum characterization of h…
The early stage of massive galaxy evolution often involves outflows driven by a starburst or a central quasar plus cold mode accretion (infall), which adds to the mass build-up in the galaxies. To study the nature of these infall and…
We measure the spectral properties of a representative sub-sample of 187 quasars, drawn from the Parkes Half-Jansky, Flat-radio-spectrum Sample (PHFS). Quasars with a wide range of rest-frame optical/UV continuum slopes are included in the…
(Abridged) We report on the X-ray and multiwavelength properties of 11 radio-quiet quasars with weak or no emission lines identified by the Sloan Digital Sky Survey (SDSS) with redshift z=0.4-2.5. The distribution of relative X-ray…
We present a moderate resolution (~1.15 Angstroms/pixel) survey of 79 quasars obtained using the Kast spectrograph on the Shane 3m telescope at Lick observatory. The spectra span the wavelength range of 3175-5880 Angstroms, and have typical…
We use optical and near-IR imaging to examine the properties of the significant excess population of K>=19 galaxies found in the fields of 31 z=1-2 radio-loud quasars by Hall, Green & Cohen (1998). The excess occurs on two spatial scales: a…
We present Keck spectropolarimetry of two rare low-ionization broad absorption line (BAL) QSOs, FIRST J084044.5+363328 and FIRST J155633.8+351758, that also exhibit narrow absorption lines from metastable excited levels of Fe II (``Iron…
We use Southern African Large Telescope (SALT) to perform long-slit spectroscopic observations of 23 newly discovered radio-loud quasars (RLQs) at $2.7<z<3.3$. The sample consists of powerful AGN brighter than 200 mJy at 1.4 GHz and is…
We present high angular resolution imaging of the quasar PSO J172.3556+18.7734 at $z=6.82$ with the Very Long Baseline Array (VLBA). This source currently holds the record of being the highest redshift radio-loud quasar. These observations…
This paper reports very-long-baseline interferometry observations of the radio-loud broad absorption line (BAL) quasar J1020+4320 at 1.7, 2.3, 6.7, and 8.4 GHz using the Japanese VLBI network (JVN) and European VLBI network (EVN). The radio…
We present the radio properties of optically selected quasars with $z\geq3$. The complete sample consists of 102 quasars with a flux density level $S_{1.4}\geq100$ mJy in a declination range -35$^{\circ}$ $\leq$ Dec $\leq$ +49$^{\circ}$.…
We study the differences in physical properties of quasar-host galaxies using an optically selected sample of radio loud (RL) and radio quiet (RQ) quasars (in the redshift range 0.15 < z < 1.9) which we have further cross-matched with the…
We present optical light curves of 19 radio quiet (RQ) broad absorption line (BAL) QSOs and study their rapid variability characteristics. Systematic CCD observations, aided by a careful data analysis procedure, have allowed us to clearly…
While there are a lot of investigations on the optical variability of flat-spectrum radio quasars (FSRQs), not much work has been done on the optical variability of steep-spectrum radio quasars (SSRQs). We investigate the optical…
We examine the UV and X-ray properties of 256 radio-quiet SDSS quasars (QSOs) observed in X-rays with Chandra and/or XMM-Newton in order to study the relationship between QSOs with broad CIV absorption lines (BALs; width >2000 km/s) and…
Broad Absorption Line Quasars (BALQs) generally exhibit significant outflows that may interact with the surrounding medium, resulting in radio emission. We selected a sample of 13 powerful radio-quiet (RQ) BALQs, where the UV outflow…
We have investigated a sample of 5088 quasars from the Sloan Digital Sky Survey Second Data Release in order to determine how the frequency and properties of broad absorptions lines (BALs) depend on black hole mass, bolometric luminosity,…
The main goal of the FIRST-APM QSO Survey (FAQS) survey is to compile the most complete sample of Bright QSOs, located in the well optically investigated area of the sky covered by the Second Byurakan Survey (SBS). We do that through the…
We have constructed a sample of radio-loud and radio-quiet quasars from the Faint Im- ages Radio Sky at Twenty-one centimetres (FIRST) and the Sloan Digital Sky Survey Data Release 7 (SDSS DR7), over the H-ATLAS Phase 1 Area (9h, 12h and…
We present results from the largest systematic investigation of broad absorption line (BAL) acceleration to date. We use spectra of 140 quasars from three Sloan Digital Sky Survey programs to search for global velocity offsets in BALs over…
We study the transient (i.e. emerging or disappearing) C IV broad absorption line (BAL) components in 50 radio detected QSOs using multi-epoch spectra available in Sloan Digital Sky Survey DR10. We report the detectionof 6 BALQSOs having at…