Related papers: Classifying Broad Absorption Line Quasars: Metrics…
We present a catalog of 224 broad absorption line quasars (BALQSOs) from the Sloan Digital Sky Survey's Early Data Release Quasar Catalog, including a relatively complete and homogeneous subsample of 131 BALQSOs. Since the identification of…
We have applied a Learning Vector Quantization (LVQ) algorithm to SDSS DR5 quasar spectra in order to create a large catalogue of broad absorption line quasars (BALQSOs). We first discuss the problems with BALQSO catalogues constructed…
Quasars that exhibit blue-shifted, broad absorption lines (BAL QSOs) are an important probe of black hole feedback on galaxy evolution. Yet the presence of BALs is also a complication for large, spectroscopic surveys that use quasars as…
Broad Absorption Line Quasars (BALQSOs) displaying distinct blue-shifted broad absorption lines. These serve as invaluable probes for unraveling the intricate structure and evolution of quasars, shedding light on the profound influence…
We carefully reconsider the problem of classifying broad absorption line quasars (BALQSOs) and derive a new, unbiased estimate of the intrinsic BALQSO fraction from the SDSS DR3 QSO catalogue. We first show that the distribution of objects…
We present a catalog of 5039 broad absorption line (BAL) quasars (QSOs) in the Sloan Digital Sky Survey (SDSS) Data Release 5 (DR5) QSO catalog that have absorption troughs covering a continuous velocity range >= 2000 km/s. We have fit…
A sample of 67 Broad Absorption Line quasars (BALQSOs) from the Large Bright Quasar Survey (LBQS) is used to estimate the observed and intrinsic fraction of BAL quasars in optically--selected samples at intermediate (B_J \simeq 18.5)…
We describe the application of non-negative matrix factorisation to generate compact reconstructions of quasar spectra from the Sloan Digital Sky Survey (SDSS), with particular reference to broad absorption line quasars (BALQSOs). BAL…
The intrinsic fraction of broad absorption line quasars (BALQSOs) is important in constraining geometric and evolutionary models of quasars. We present the fraction of BALQSOs in 2MASS detected quasars within the SDSS DR3 sample in the…
There is growing evidence of a higher intrinsic fraction of broad absorption line quasars (BALQSOs) than that obtained in optical surveys, on which most previous X-ray studies of BALQSOs have focused. Here we present Chandra observations of…
We investigate the continuum and emission-line properties of 224 broad absorption line quasars (BALQSOs) with 0.9<z<4.4 drawn from the Sloan Digital Sky Survey (SDSS) Early Data Release (EDR), which contains 3814 bona fide quasars. We find…
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…
A new broad absorption line quasar (BAL) sample is derived from the first data released by the Sloan Digital Sky Survey. With 116 objects, it is the largest BAL sample yet assembled. Over the redshift range 1.8 < z < 3.8, the crude fraction…
We present a time-variability analysis of 29 broad absorption line quasars (BALQSOs) observed in two epochs by the Sloan Digital Sky Survey (SDSS). These spectra are selected from a larger sample of BALQSOs with multiple observations by…
Spectropolarimetry of Broad Absorption Line Quasars (BALQSO's) has demonstrated that the geometry of the absorbing material is far from spherically symmetric. Calculations of accretion disk spectra suggest that the intrinsic radiation…
It is been known for more than a decade that BALQSOs (broad absorption line quasars) are highly attenuated in the X-ray regime compared to other quasars, especially in the soft band ($< $ 1 keV). Using X-ray selection techniques we have…
Broad absorption line (BAL) quasars serve as critical probes for understanding active galactic nucleus (AGN) outflows, black hole accretion, and cosmic evolution. To address the limitations of manual classification in large-scale…
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…
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…
Recent results from the ROSAT All-Sky Survey (RASS) have shown that broad absorption line (BAL) QSOs are either highly absorbed or underluminous in the soft X-ray bandpass. Here, we extend this work by analyzing all known bona fide BALQSOs…