Results 11 to 20 of about 515 (214)
A Left and Right Truncated Schechter Luminosity Function for Quasars [PDF]
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
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
openaire +3 more sources
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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Pictor A: A new double-peaked emission-line quasar [PDF]
The Astrophysical Journal, 1995 uu-encoded compressed tar of postscript files.
Sulentic, J. W. +3 more
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Spectroscopic follow-up of double quasar candidates [PDF]
Monthly Notices of the Royal Astronomical Society, 2018 8 pages, 7 figures, 5 tables (full tables 1 and 3-5 are available online in a machine-readable ASCII format at https://grupos.unican.es/glendama/LQLM_results.htm). Accepted for publication in MNRAS (uncorrected version)
Shalyapin, V. N. +3 more
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Modelling accretion disk winds in quasars [PDF]
, 2014 Outflows are ubiquitous in active galactic nuclei (AGN). They can take the form of either dramatic radio jets, which extend vast distances into the inter-galactic medium, or of much smaller scale winds - whose existence can be inferred only indirectly ...
Nick Higginbottom +1 more
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