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Related papers: Broad Absorption Line Variability in Radio-Loud Qu…

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We present results of our time variability studies of Mg II and Al III absorption lines in a sample of 22 Low Ionization Broad Absorption Line QSOs (LoBAL QSOs) at 0.2 <= zem <= 2.1 using the 2m telescope at IUCAA Girawali Observatory over…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 M. Vivek , R. Srianand , P. Petitjean , V. Mohan , A. Mahabal , S. Samui

We investigate the connection between the intrinsic C IV absorption line variability and the continuum flux changes of broad absorption line (BAL) quasars using a sample of 78 sources in the Stripe 82 region. The absorption trough…

Astrophysics of Galaxies · Physics 2019-04-10 M. Vivek

We have obtained single-epoch optical photometry for 201 quasars, taken from the FIRST Bright Quasar Survey, which span a wide range in radio loudness. Comparison with the magnitudes of these objects on the POSS-I plates provides by far the…

Recent works showed that the absorbing material in broad absorption line (BAL) quasars is optically thick to major resonant absorption lines. This material may contribute significantly to the polarization in the absorption lines. In this…

Astrophysics · Physics 2009-11-11 Hui-Yuan Wang , Ting-Gui Wang , Jun-Xian Wang

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 incidence of broad absorption lines (BALs) in quasar samples is often interpreted in the context of a geometric unification model consisting of an accretion disc and an associated outflow. We use the the Sloan Digital Sky Survey (SDSS)…

Astrophysics of Galaxies · Physics 2017-02-08 James H. Matthews , Christian Knigge , Knox S. Long

We present preliminary results from a reverberation mapping program to measure the Broad Line Region size in high-redshift, high-luminosity quasars. The observations are carried out at the Hobby-Eberly Telescope and at the Wise Observatory.…

Astrophysics · Physics 2007-05-23 Shai Kaspi , Hagai Netzer , Dan Maoz , Ohad Shemmer , W. N. Brandt , Donald P. Schneider

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…

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…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Tuo Ji , Tinggui Wang , Hongyan Zhou , Huiyuan Wang

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 a sample of 68 low-z MgII low-ionization broad absorption-line (loBAL) quasars. The sample is uniformly selected from the SDSS5 according to the following criteria: (1) 0.4<z<0.8, (2) median S/N>7, and (3) MgII absorption-line…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Shaohua Zhang , Ting-Gui Wang , Huiyuan Wang , Hongyan Zhou , Xiao-Bo~Dong , Jian-Guo Wang

We present the results of an extension of the FIRST Bright Quasar Survey (FBQS) to the South Galactic cap, and to a fainter optical magnitude limit. Radio source counterparts with SERC R magnitudes brighter than 18.9 which meet the other…

We analyze VLT/X-shooter data for 7 quasars, where we study the relationships between their broad absorption line (BAL) and emission line outflows. We find: 1) the luminosity of the [OIII] $\lambda$5007 emission profile decreases with…

Astrophysics of Galaxies · Physics 2020-05-13 Xinfeng Xu , Nadia Zakamska , Nahum Arav , Timothy Miller , Chris Benn

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…

Astrophysics of Galaxies · Physics 2025-11-04 Yangyang Li , Zhijian Luo , Shaohua Zhang , Du Wang , Jianzhen Chen , Zhu Chen , Hubing Xiao , Chenggang Shu

The Sloan Digital Sky Survey has discovered a population of broad absorption line quasars with various extreme properties. Many show absorption from metastable states of FeII with varying excitations; several objects are almost completely…

In this article, the hydrogen column densities derived from X-ray observations of type II (hidden) quasars and broad absorption line quasars (BALQSOs) are compared. These column densities represent the amount of absorbing material between…

Astrophysics · Physics 2011-02-11 Brian Punsly

We study the relationship between the broad absorption lines (BALs) that can be decomposed into multiple narrow absorption lines and those that cannot (hereafter Type N and Type S BAL, respectively), based on the analysis of three BAL…

Astrophysics of Galaxies · Physics 2019-09-04 Wei-Jian Lu , Ying-Ru Lin

We isolate a set of quasars that exhibit emergent C iv broad absorption lines (BALs) in their spectra by comparing spectra in the SDSS Data Release 7 and the SDSS/BOSS Data Releases 9 and 10. After visually defining a set of emergent BALs,…

We probe the small-scale absorption line variability using absorption depth based analysis of a sample of 64 ultra-fast outflow (UFO) C IV broad absorption line (BAL) quasars monitored using the Southern African Large Telescope. We confirm…

Astrophysics of Galaxies · Physics 2024-01-01 P. Aromal , R. Srianand , P. Petitjean

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…