Results 11 to 20 of about 365 (183)
The intrinsic fraction of broad-absorption line quasars [PDF]
Monthly Notices of the Royal Astronomical Society, 2008 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 selected by the so-called ``absorption index'' (AI) is clearly bimodal in log(AI), with only one mode ...
Knigge, Christian +3 more
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Radio Emission from Broad Absorption Line Quasars
The Astrophysical JournalBroad Absorption Line Quasars (BALQs) generally exhibit significant outflows that may interact with the surrounding medium, resulting in radio emission.
Sina Chen +3 more
doaj +3 more sources
The orientation and polarization of broad absorption line quasars★ [PDF]
Monthly Notices of the Royal Astronomical Society, 2012 We present new spectropolarimetric observations of 8 radio-loud broad absorption line (BAL) quasars, and combine these new data with our previous spectropolarimetric atlases (of both radio-loud and radio-quiet objects) in order to investigate the polarization properties of BAL quasars as a group.
DiPompeo, M. A. +2 more
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A Balmer-line Broad Absorption Line Quasar [PDF]
The Astronomical Journal, 2006 I report the discovery of blueshifted broad absorption line (BAL) troughs in at least six transitions of the Balmer series of hydrogen (Hbeta to H9) and in CaII, MgII and excited FeII in the quasar SDSS J125942.80+121312.6. This is only the fourth active galactic nucleus known to exhibit Balmer absorption, all four in conjunction with low-ionization ...
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Continuum and Emission-Line Properties of Broad Absorption Line Quasars [PDF]
The Astronomical Journal, 2003 35 pages, 11 figures (1 color), 1 table; accepted by ...
Reichard, TA +8 more
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AChandraSurvey of Broad Absorption Line Quasars [PDF]
The Astrophysical Journal, 2001 12 pages, Latex, emulateapj style, including 3 tables and 3 figures. Accepted May 15, 2001 for publication in ApJ Main Journal. See also http://hea-www.harvard.edu/~pgreen/Papers.html Replaced May 21 since 2 lines were missing from Table ...
Green, Paul J. +4 more
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SPECTROPOLARIMETRY OF RADIO-SELECTED BROAD ABSORPTION LINE QUASARS [PDF]
The Astrophysical Journal Supplement Series, 2010 We report spectropolarimetry of 30 radio-selected broad absorption line (BAL) quasars with the Keck Observatory, 25 from the sample of Becker et al. (2000). Both high and low-ionization BAL quasars are represented, with redshifts ranging from 0.5 to 2.5. The spectropolarimetric properties of radio-selected BAL quasars are very similar to those of radio-
DiPompeo, M. A. +6 more
openaire +2 more sources
Appearance versus disappearance of broad absorption line troughs in quasars [PDF]
Monthly Notices of the Royal Astronomical Society, 2021 ABSTRACT We present a new set of 84 broad absorption line (BAL) quasars (1.7 < zem < 4.4) exhibiting an appearance of C iv BAL troughs over 0.3–4.8 rest-frame years by comparing the Sloan Digital Sky Survey Data Release (SDSSDR)-7, SDSSDR-12, and SDSSDR-14 quasar catalogues. We contrast the nature of BAL variability in this
Mishra, Sapna +3 more
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Submillimeter Observations of a Sample of Broad Absorption Line Quasars [PDF]
The Astrophysical Journal, 2003 The broad absorption line (BAL) features seen in a small fraction of quasar optical/UV spectra are attributed to bulk outflows away from the quasar core. Observational evidence suggests that dust plays a key role in these systems, although whether the inferred dust properties are a signature of orientation effects or whether they are indicative of an ...
Lewis, Geraint F. +2 more
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Emergence and Variability of Broad Absorption Line Quasar Outflows [PDF]
The Astrophysical Journal, 2018 Abstract We isolate a set of quasars that exhibit emergent C iv broad absorption lines (BALs) in their spectra by comparing spectra in the Sloan Digital Sky Survey (SDSS) Data Release 7 and the SDSS/BOSS Data Releases 9 and 10. After visually defining a set of emergent BALs, follow-up observations were obtained with the Gemini ...
J. A. Rogerson +5 more
openaire +4 more sources