Results 21 to 30 of about 512 (214)
Statistics of Galactic-scale Quasar Pairs at Cosmic Noon
The Astrophysical Journal, 2023 The statistics of galactic-scale quasar pairs can elucidate our understanding of the dynamical evolution of supermassive black hole (SMBH) pairs, the duty cycles of quasar activity in mergers, or even the nature of dark matter, but they have been ...
Yue Shen +10 more
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4C02.27: what is inside a double-double radio quasar? [PDF]
Proceedings of 10th European VLBI Network Symposium and EVN Users Meeting: VLBI and the new generation of radio arrays — PoS(10th EVN Symposium), 2011 4 pages, 2 figures, to appear in the proceedings of the 10th European VLBI Network Symposium (September 20-24, 2010, Manchester, UK).
Frey, S., Paragi, Z.
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The Astronomical Journal, 2023 We present the first results from a new survey for high-redshift ( z ≳ 5) gravitationally lensed quasars and close quasar pairs. We carry out candidate selection based on the colors and shapes of objects in public imaging surveys, then conduct follow-up ...
Minghao Yue +3 more
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Microlensing in the double quasar SBS 1520+530 [PDF]
Astronomy & Astrophysics, 2005 6 pages, 7 figures.
Gaynullina, E. R. +9 more
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Quasar Luminosity Function at z = 7
The Astrophysical Journal Letters, 2023 We present the quasar luminosity function (LF) at z = 7, measured with 35 spectroscopically confirmed quasars at 6.55 < z < 7.15. The sample of 22 quasars from the Subaru High- z Exploration of Low-Luminosity Quasars (SHELLQs) project, combined with 13 ...
Yoshiki Matsuoka +43 more
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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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The Astrophysical Journal Letters, 2023 We report Hubble Space Telescope (HST) Wide Field Camera 3 deep IR (F160W) imaging of SDSS J1608+2716. This system, located at a redshift of z = 2.575, was recently reported as a triple-quasar candidate with subarcsecond separations (∼0.″25) based on ...
Junyao Li +7 more
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The Astrophysical Journal, 2023 Dual quasars at small physical separations are an important precursor phase of galaxy mergers, ultimately leading to the coalescence of the two supermassive black holes.
Arran C. Gross +10 more
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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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The Astrophysical Journal, 2023 Dual and off-nucleus active supermassive black holes are expected to be common in the hierarchical structure formation paradigm, but their identification at parsec scales remains a challenge due to strict angular resolution requirements.
Yu-Ching Chen +7 more
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