Two New Gravitationally Lensed Double Quasars from the Sloan Digital Sky Survey [PDF]
, 2006 We report the discoveries of the two-image gravitationally lensed quasars SDSS J074653.03+440351.3 and SDSS J140624.82+612640.9, selected from the Sloan Digital Sky Survey (SDSS).
N. Inada +9 more
semanticscholar +1 more source
Spectroscopy of the double quasars Q1343+266A, B: The relationship between galaxies and quasi-stellar object C IV absorption lines [PDF]
, 1994 We present spectra of QSOs 1343+266 A B, covering Ly-beta to C~IV emission at 2\AA~resolution, and find further evidence that this system is not gravitationally lensed.
A. Crotts +2 more
semanticscholar +1 more source
Finding Multiply Lensed and Binary Quasars in the DESI Legacy Imaging Surveys
The Astrophysical Journal Supplement Series, 2023 The time delay between multiple images of strongly lensed quasars is a powerful tool for measuring the Hubble constant ( H _0 ). To achieve H _0 measurements with higher precision and accuracy using the time delay, it is crucial to expand the sample of ...
C. Dawes +6 more
doaj +1 more source
The double quasar Q2138 -- 431: lensing by a dark galaxy? [PDF]
Monthly Notices of the Royal Astronomical Society, 1997 We report the discovery of a new gravitational lens candidate Q2138-431AB, comprising two quasar images at a redshift of 1.641 separated by 4.5 arcsecs. The spectra of the two images are very similar, and the redshifts agree to better than 115 km.sec$^{-1}$. The two images have magnitudes $B_J = 19.8$ and $B_J = 21.0$, and in spite of a deep search and
Hawkins, MRS +6 more
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Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). V. Quasar Luminosity Function and Contribution to Cosmic Reionization at z = 6 [PDF]
Astrophysical Journal, 2018 We present new measurements of the quasar luminosity function (LF) at z ∼ 6 over an unprecedentedly wide range of the rest-frame ultraviolet luminosity M1450 from −30 to −22 mag.
Y. Matsuoka +46 more
semanticscholar +1 more source
Modelling the Gravitational Lens of the Double Quasar [PDF]
Symposium - International Astronomical Union, 1982 The discovery of the double quasar (Walsh ET AL. 1979) provides an opportunity to study the mass distribution of elliptical galaxies and clusters of galaxies. This has been done initially by Young ET AL. (1981) who produced a model to account for the image positions and intensities. Since then VLBI observations have been made of 0957+561A and B (Porcas
P. K. Moore, S. M. Harding
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Unusual double-peaked emission in the SDSS quasar J093201.60+031858.7 [PDF]
New Astronomy, 2011 Author list updated in version 2; 17 pages; 3 figures; accepted for publication in New ...
Barrows, R. Scott +4 more
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Revisiting X-Ray-bright Optically Normal Galaxies with the Chandra Source Catalog
The Astrophysical Journal, 2023 X-ray bright optically normal galaxies (XBONGs) are galaxies with X-ray luminosities consistent with those of active galactic nuclei (AGNs) but no evidence of AGN optical emission lines.
Dong-Woo Kim +5 more
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THE QUASAR SDSS J1536+0441: AN UNUSUAL DOUBLE-PEAKED EMITTER [PDF]
The Astrophysical Journal, 2010 The quasar SDSS J153636.22+044127.0, exhibiting peculiar broad emission-line profiles with multiple components, was proposed as a candidate sub-parsec binary supermassive black hole system. More recently, imaging revealed two spatially distinct sources, leading some to suggest the system to be a quasar pair separated by ~5 kpc.
Chornock, Ryan +9 more
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Discovery of a quasar with double-peaked broad balmer emission lines
Monthly Notices of the Royal Astronomical Society: Letters, 2022 ABSTRACT Most massive galaxies contain a supermassive black hole (SMBH) at their centre. When galaxies merge, their SMBHs sink to the centre of the new galaxy, where they are thought to eventually merge. During this process, an SMBH binary is formed.
Jacco H Terwel, Peter G Jonker
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