Results 21 to 30 of about 365 (183)
Broad absorption line variability in radio-loud quasars [PDF]
Monthly Notices of the Royal Astronomical Society, 2014 We investigate C IV broad absorption line (BAL) variability within a sample of 46 radio-loud quasars (RLQs), selected from SDSS/FIRST data to include both core-dominated (39) and lobe-dominated (7) objects. The sample consists primarily of high-ionization BAL quasars, and a substantial fraction have large BAL velocities or equivalent widths; their ...
Welling, C. A. +4 more
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A sensitive submillimetre survey of broad absorption-line quasars [PDF]
Monthly Notices of the Royal Astronomical Society, 2007 Using the SCUBA bolometer array on the JCMT, we have carried out a submillimetre survey of Broad Absorption Line quasars (BALQs). The sample has been chosen to match, in redshift and optical luminosity, an existing benchmark 850um sample of radio-quiet quasars, allowing a direct comparison of the submm properties of BAL quasars relative to the parent ...
Priddey, R. S. +5 more
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Microlensing of broad absorption line quasars
Monthly Notices of the Royal Astronomical Society, 1998 The physical nature of the material responsible for the high--velocity, broad-absorption line features seen in a small fraction of quasar spectra has been the subject of debate since their discovery. This has been especially compounded by the lack of observational probes of the absorbing region.
Lewis, Geraint F., Belle, Kunegunda E.
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The Submillimeter Properties of Broad Absorption Line Quasars
The Astrophysical Journal, 2003 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 2 sigma significance, four of which are at > 3 sigma significance.
Willott, Christopher +2 more
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Variability in Quasar Broad Absorption Line Outflows [PDF]
Proceedings of the International Astronomical Union, 2009 Broad absorption lines (BALs) in quasar spectra identify high-velocity outflows that likely exist in all quasars and could play a major role in feedback to galaxy evolution (e.g., Di Matteo et al. 2005). Studying the variability in these BALs can help us understand the structure, evolution, and basic physical properties of these outflows.
Daniel M. Capellupo +4 more
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Spectropolarimetry of FIRST Broad Absorption Line Quasars [PDF]
The Astrophysical Journal, 1997 We present Keck spectropolarimetry of two rare low-ionization broad absorption line (BAL) quasars (QSOs), FIRST J084044.5+363328 and FIRST J155633.8+351758, that also exhibit narrow absorption lines from metastable excited levels of Fe II (iron Lo-BALs).
M. S. Brotherton +4 more
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The X‐Ray Absorber in Broad Absorption Line Quasars
The Astrophysical Journal, 2000 11 pages, 6 figures, replacement of figure ...
Wang, T. G. +4 more
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On the Continuum Shape of Broad Absorption Line Quasars [PDF]
Publications of the Astronomical Society of Japan, 1999 The continuum shape of 26 broad absorption line (BAL) QSOs is shown to be virtually identical to that of non-BAL QSOs when the spectra of the former are dereddened. A procedure for dereddening of BAL QSO spectra is introduced, based on measurement of the flux in three bands and determination of the colour excess in comparison with an unreddened ...
Tetsuo M. Yamamoto, Vladas Vansevičius
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Modeling Line-Driven Disk Wind for Broad Absorption Lines of Quasars [PDF]
Publications of the Astronomical Society of Japan, 2013 Abstract The disk wind, which is powered by the radiation force due to spectral lines (line force), has been studied concerning broad absorption line (BAL) quasars. We investigated the structure of the disk wind based on a non-hydrodynamic method, and compared it with wind properties inferred from X-ray observations of BAL quasars.
Nomura, Mariko +4 more
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THE VIEWING ANGLES OF BROAD ABSORPTION LINE VERSUS UNABSORBED QUASARS [PDF]
The Astrophysical Journal, 2012 It was recently shown that there is a significant difference in the radio spectral index distributions of broad absorption line (BAL) quasars and unabsorbed quasars, with an overabundance of BAL quasars with steeper radio spectra. This result suggests that source orientation does play into the presence or absence of BAL features.
DiPompeo, Michael A. +2 more
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