Results 21 to 30 of about 16,078 (195)
Quasar Broad Absorption Line Variability on Multiyear Timescales [PDF]
The Astrophysical Journal, 2008 To be published in ...
Gibson, Robert R. +3 more
openaire +2 more sources
The Astrophysical Journal, 2022 We analyze Very Large Telescope/UVES observations of the quasar SDSS J024221.87+004912.6. We identify four absorption outflow systems: a C iv broad absorption line (BAL) at v ≈ −18,000 km s ^−1 and three narrower low-ionization systems with centroid ...
Doyee Byun, Nahum Arav, Patrick B. Hall
doaj +1 more source
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
openaire +3 more sources
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
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
openaire +2 more sources
New Constraints on Quasar Broad Absorption and Emission Line Regions from Gravitational Microlensing
Frontiers in Astronomy and Space Sciences, 2017 Gravitational microlensing is a powerful tool allowing one to probe the structure of quasars on sub-parsec scale. We report recent results, focusing on the broad absorption and emission line regions.
Damien Hutsemékers +4 more
doaj +1 more source
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
Discovery of Two Spectroscopically Peculiar, Low-Luminosity Quasars at z~4 [PDF]
, 2007 We report the discovery of two low-luminosity quasars at z~4, both of which show prominent N IV] 1486A emission. This line is extremely rare in quasar spectra at any redshift; detecting it in two out of a sample of 23 objects (i.e., ~ 9% of the sample ...
Ashish Mahabal +5 more
core +2 more sources
Properties of X-ray-selected broad absorption-line quasars★ [PDF]
Monthly Notices of the Royal Astronomical Society, 2008 13 pages, 8 figures, accepted for publication in ...
Blustin, A. J. +8 more
openaire +5 more sources
The Astrophysical Journal Letters, 2023 We report the discovery of COOL J0335−1927, a quasar at z = 3.27 lensed into three images with a maximum separation of 23.″3 by a galaxy cluster at z = 0.4178. To date, this is the highest redshift wide-separation lensed quasar known.
Kate Napier +20 more
doaj +1 more source