Results 11 to 20 of about 512 (214)
Relativistic beaming in the central components of double radio quasars [PDF]
Journal of Astrophysics and Astronomy, 1982 Using a large sample of 78 well-observed double quasars, we have investigated several consequences of the relativistic beaming model. In this model the ratio of the strengths of the central component and outer lobes of a double source depends on whether ...
V K Kapahi, D J Saikia, Saikia D J
exaly +3 more sources
A Catalog of Candidate Double and Lensed Quasars from Gaia and WISE Data
The Astrophysical Journal Supplement Series, 2022 Making use of strong correlations between closely separated multiple or double sources and photometric and astrometric metadata in Gaia Early Data Release 3 (EDR3), we generate a catalog of candidate double- and multiply imaged lensed quasars and active ...
Valeri V. Makarov, Nathan J. Secrest
doaj +3 more sources
Double Lobed Radio Quasars from the Sloan Digital Sky Survey [PDF]
The Astronomical Journal, 2005 We have combined a sample of 44 984 quasars, selected from the Sloan Digital Sky Survey (SDSS) Data Release 3, with the FIRST radio survey. Using a novel technique where the optical quasar position is matched to the complete radio environment within 450''
de Vries, W. H. +5 more
core +4 more sources
DOUBLE QUASARS: PROBES OF BLACK HOLE SCALING RELATIONSHIPS AND MERGER SCENARIOS [PDF]
Astrophysical Journal, 2009 ApJ in ...
Foreman, G, Volonteri, M, DOTTI, MASSIMO
exaly +3 more sources
Quasars with Proper Motions and the Link to Double and Multiple AGNs
Astrophysical Journal, 2022 Abstract Gaia used a large sample of photometrically selected active galactic nuclei (AGNs) and quasars to remove the residual spin of its global proper motion system in order to achieve a maximally inertial reference frame. A small fraction of these reference objects have statistically significant astrometric proper motions in Gaia EDR3.
Valeri V Makarov, Nathan J Secrest
exaly +3 more sources
Gravitationally lensed quasars in Gaia – II. Discovery of 24 lensed quasars
Monthly Notices of the Royal Astronomical Society, 2018 We report the discovery, spectroscopic confirmation, and preliminary characterization of 24 gravitationally lensed quasars identified using Gaia observations.
C Lemon +2 more
exaly +3 more sources
A hidden population of high-redshift double quasars unveiled by astrometry [PDF]
Nature Astronomy, 2021 Galaxy mergers occur frequently in the early universe and bring multiple supermassive black holes (SMBHs) into the nucleus, where they may eventually coalesce. Identifying post-merger-scale (i.e., 2, but critical to constraining the progenitors of SMBH mergers.
Yue Shen +2 more
exaly +3 more sources
A Left and Right Truncated Schechter Luminosity Function for Quasars
Galaxies, 2017 The luminosity function for quasars (QSOs) is usually fitted by a Schechter function. The dependence of the number of quasars on the redshift, both in the low and high luminosity regions, requires the inclusion of a lower and upper boundary in the ...
Lorenzo Zaninetti
doaj +2 more sources
Evidence for the class of the most luminous quasars
Astronomy and Astrophysics, 2001 We study the radio properties of the optically luminous "AI" subclass of quasars at $M_{V} \approx -26.0$ ($H_{\rm 0}=100$ km s-1/Mpc, $q_{\rm 0} = \frac{1}{2}$; Teerikorpi [CITE], [CITE]; Papers I, II), after first results on double sources in Paper I ...
P Teerikorpi
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A Candidate Dual QSO at Cosmic Noon
The Astrophysical Journal Letters, 2023 We report the discovery of a candidate dual QSO at z = 1.889, a redshift that is in the era known as “cosmic noon” where most of the universe’s black hole and stellar mass growth occurred.
Eilat Glikman +8 more
doaj +1 more source