Related papers: Exploratory ASCA Observations of Broad Absorption …

The origin of broad-absorption-line quasars (BAL QSOs) is still an open issue. Accounting for ~20% of the QSO population, these objects present broad absorption lines in their optical spectra generated from outflows with velocities up to…

We present a study of the low-frequency radio properties of broad absorption line quasars (BALQSOs) from the LOFAR Two-metre Sky-Survey Data Release 1 (LDR1). The value-added LDR1 catalogue contains Pan-STARRS counterparts, which we match…

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 present combined $\approx 14-37~\rm ks$ Chandra observations of seven $z = 1.6-2.7$ broad absorption line (BAL) quasars selected from the Large Bright Quasar Survey (LBQS). These seven objects are high-ionization BAL (HiBAL) quasars, and…

Recent XMM-Newton observations of the high-redshift, lensed, broad absorption line (BAL) quasi-stellar object APM 08279+5255, one of the most luminous objects in the universe, allowed the detection of a high column density absorber ($N_H…

We perform a survey of the X-ray properties of 41 objects from the WISE/SDSS selected Hyper-luminous (WISSH) quasars sample, composed by 86 broad-line quasars (QSOs) with bolometric luminosity $L_{Bol}\geq 2\times 10^{47}\,erg\, s^{-1}$, at…

Broad absorption line (BAL) quasars are often considered X-ray weak relative to their optical/UV luminosity, whether intrinsically (i.e., the coronal emission is fainter) or due to large column densities of absorbing material. The SDSS-V is…

We have carried out the first systematic survey of the sub-millimeter properties of broad absorption line (BAL) quasars. 30 BAL quasars drawn from a homogeneously selected sample from the Sloan Digital Sky Survey at redshifts 2<z<2.6 were…

We have built a sample of 74 radio-selected broad absorption line quasars from the Sloan Digital Sky Survey Data Release 5 (SDSS DR5) and Faint Images of the Radio Sky at Twenty Centimeters (FIRST), along with a well matched sample of 74…

We report on the results of XMM-Newton observations of two Broad Absorption Line Quasars (BAL QSOs), Q1246-057 and SBS 1542+541. Unprecedented sensitivity of XMM allows spectral analysis of these X-ray weak sources. The X-ray spectral data…

Highly polarized QSOs discovered in the Two-Micron All Sky Survey (2MASS) have been observed to determine the source(s) of optical polarization in this near-infrared color-selected sample. Broad emission lines are observed in the polarized…

We present \textit{Chandra} observations of the radio-quiet Broad Absorption Line (BAL) QSO PG 1254+047. We find that it is a weak X-ray source, with a total of $44\pm 7$ photons measured in 36 ksec across the observed energy range $0.7 -…

Deep hard X-ray and near infrared observations of a type-2 radio-quiet QSO candidate at z=0.9, AXJ08494+4454, are reported. The 0.5-10keV Chandra X-ray Observatory spectrum of AXJ08494+4454 is hard, and is explained well with a power-law…

Broad absorption line quasars (BAL QSOs) belong to a class of objects not well-understood as yet. Their UV spectra show BALs in the blue wings of the UV resonance lines, owing to ionized gas with outflow velocities up to 0.2 c. They can…

We use UKIRT and ASCA observations to determine the nature of a high redshift (z=2.35) narrow-line AGN, previously discovered by Almaini et al. (1995). The UKIRT observations show a broad Halpha line while no Hbeta line is detected. This…

We present the results of optical spectroscopic identifications of a bright subsample of 2-10keV hard X-ray selected sources from the ASCA Medium Sensitivity Survey in the northern sky. The flux limit of the subsample is 3*10^-13 erg s^-1…

We describe the motivation and features of a multiwavelength spectroscopic campaign on broad absorption line (BAL) QSO PG~0946+301. The main goal of this project is to determine the ionization equilibrium and abundances (IEA) in BAL…

Results are presented on the X-ray properties of 9 high-redshift (1.2 < z < 3.4) radio-loud quasars (RLQs) observed by ASCA (10 observations) and ROSAT (11 observations, for a subset of 6 quasars). New ASCA observations of S5 0014+81 (z =…

We report the discovery of Balmer broad absorption lines (BALs) in the quasar LBQS 1206+1052 and present a detailed analysis of the peculiar absorption line spectrum. Besides Mg II $\lambda \lambda 2796, 2803$ doublet, BALs are also…

We present the first results of the Chandra and optical follow-up observations of hard X-ray sources detected in the ASCA Medium Sensitivity Survey (AMSS). Optical identifications are made for five objects. Three of them show either weak or…