High Metal Content of Highly Accreting Quasars [PDF]
Astrophysical Journal, 2020 We present an analysis of UV spectra of 13 quasars believed to belong to extreme Population A (xA) quasars, aimed at the estimation of the chemical abundances of the broad-line-emitting gas.
M. Śniegowska +6 more
semanticscholar +1 more source
Fundamental differences in the radio properties of red and blue quasars: kiloparsec-scale structures revealed by e-MERLIN [PDF]
, 2021 Red quasi-stellar objects (QSOs) are a subset of the quasar population with colours consistent with reddening due to intervening dust. Recent work has demonstrated that red QSOs show special radio properties that fundamentally distinguish them from ...
D. Rosario +7 more
semanticscholar +1 more source
Cosmic ray generation by quasar remnants: constraints and implications [PDF]
Monthly Notices of the Royal Astronomical Society, 2000 The quasar remnant cores of nearby giant elliptical galaxies NGC 4486 (M87), NGC 1399, NGC 4649 and NGC 4472 are the sites of supermassive (greater than one billion solar masses) black holes. These objects are investigated as to the viability of the conjecture that they could harbor compact dynamos capable of generating the highest energy cosmic rays ...
Boldt, Elihu, Loewenstein, Michael
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Constraining the ratio of median pixel optical depth profile around z ∼ 4 quasars using the longitudinal proximity effect [PDF]
, 2021 We present a detailed study of the longitudinal proximity effect using a sample of 85 quasars spanning an emission redshift range of 3.5 6 zem 6 4.5 and Lyman continuum luminosity (L912) ranging from 1.06×10 31 to 2.24×10 erg s Hz.
P. Jalan, H. Chand, R. Srianand
semanticscholar +1 more source
Peculiar emission line spectra of core extremely red BOSS quasars at z∼2–3: orientation and/or evolution? [PDF]
Astronomy & Astrophysics, 2020 Context. Core extremely red quasars (core ERQ) have been proposed to represent an intermediate evolutionary phase in which a heavily obscured quasar blows out the circumnuclear interstellar medium with very energetic outflows before it becomes an optical
M. Martín +7 more
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Quasars as standard candles II [PDF]
Astronomy & Astrophysics, 2019 A tight non-linear relation between the X-ray and the optical-ultraviolet (UV) emission has been observed in active galactic nuclei (AGN) over a wide range of redshift and several orders of magnitude in luminosity, suggesting the existence of an ...
F. Salvestrini +4 more
semanticscholar +1 more source
Pulsations of primordial supermassive stars induced by a general relativistic instability; visible to JWST at z$>$12 [PDF]
, 2022 The origin of high-redshift quasars and their supermassive black hole engines is unclear. One promising solution is the collapse of a primordial supermassive star.
Chris Nagele +3 more
semanticscholar +1 more source
Erratum: Is every strong lens model unhappy in its own way? Uniform modelling of a sample of 13 quadruply+ imaged quasars [PDF]
Monthly notices of the Royal Astronomical Society, 2018 Strong-gravitational lens systems with quadruply imaged quasars (quads) are unique probes to address several fundamental problems in cosmology and astrophysics.
A. Shajib +72 more
semanticscholar +1 more source
PHOTOMETRIC REDSHIFTS AND QUASAR PROBABILITIES FROM A SINGLE, DATA-DRIVEN GENERATIVE MODEL [PDF]
The Astrophysical Journal, 2012 We describe a technique for simultaneously classifying and estimating the redshift of quasars. It can separate quasars from stars in arbitrary redshift ranges, estimate full posterior distribution functions for the redshift, and naturally incorporate flux uncertainties, missing data, and multi-wavelength photometry.
Bovy, Jo +9 more
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The nature of low-luminosity AGNs discovered by JWST based on clustering analysis: Progenitors of low-z quasars? [PDF]
Monthly notices of the Royal Astronomical SocietyJames Webb Space Telescope (JWST) has discovered many faint AGNs at high-z by detecting their broad Balmer lines. However, their high number density, lack of X-ray emission, and overly high black hole masses with respect to their host stellar masses ...
Junya Arita +6 more
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