The anticorrelation between the hard X-ray photon index and the Eddington ratio in low-luminosity active galactic nuclei [PDF]
, 2009 We find a significant anticorrelation between the hard X-ray photon index Gamma and the Eddington ratio L(bol)/L(Edd) for a sample of low-ionization nuclear emission-line regions and local Seyfert galaxies, compiled from literature with Chandra or XMM ...
Gu, Minfeng, Cao, Xinwu
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Is There a Metallicity-Luminosity Relationship in Active Galactic Nuclei? The Case of Narrow-Line Seyfert 1 Galaxies [PDF]
, 2002 This article discusses the relationship between metallicity and luminosity in active galactic nuclei by introducing new metallicity measurements for a sample of narrow-line Seyfert 1 ...
Netzer, Hagai +3 more
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The X-ray spectra of high-luminosity active galactic nuclei observed by Ginga
The Astrophysical Journal, 1992 Results are presented on the X-ray emission from 13 objects, observed by Ginga as part of a spectral survey of bright quasars in the energy range 2-20 keV. The distribution of the power-law energy index for this sample has a mean of 0.81 and shows significant intrinsic dispersion, σ = 0.31, values which are broadly compatible with those from samples of
WILLIAMS, OR +10 more
openaire +2 more sources
Letter to Nature: An ultra-relativistic outflow from a neutron star accreting gas from a companion. [PDF]
, 2004 Collimated relativistic outflows—also known as jets—are amongst the most energetic phenomena in the Universe. They are associated with supermassive black holes in distant active galactic nuclei1, accreting stellar-mass black holes and neutron stars in ...
Johnston, H. +27 more
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On the Subparsec-scale Core Composition of FR 0 Radio Galaxies
The Astrophysical Journal Letters, 2023 Although Fanaroff–Riley type 0 (FR 0) radio galaxies are known to be the most numerous jet population in the local Universe, they are much less explored than the well-established class of FR type I (FR I) and FR type II galaxies due to their intrinsic ...
Margot Boughelilba, Anita Reimer
doaj +1 more source
ON THE ORIGIN OF ULTRAVIOLET EMISSION AND THE ACCRETION MODEL OF LOW-LUMINOSITY ACTIVE GALACTIC NUCLEI [PDF]
, 2010 Low-luminosity active galactic nuclei (LLAGNs) are generally believed to be powered by an inner radiatively inefficient, advection-dominated accretion flow (ADAF), an outer truncated thin disk, and a jet.
Zhaolong Yu +5 more
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Cosmological Evolution of the Central Engine in High-Luminosity, High-Accretion Rate AGN
Acta Polytechnica CTU Proceedings, 2014 In this paper I discuss the status of observational studies aiming at probing the cosmological evolution of the central engine in high-luminosity, high-accretion rate Active Galactic Nuclei (AGN). X-ray spectroscopic surveys, supported by extensive multi-
Matteo Guainazzi
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OBSERVATIONAL EVIDENCE FOR ACTIVE GALACTIC NUCLEI FEEDBACK AT THE PARSEC SCALE [PDF]
, 2011 In a hot accretion flow, the radiation from the innermost region of the flow propagates outward and heats the electrons at large radii via Compton scattering.
Miao Li, Feng Yuan, Yuan, Feng, Li, Miao
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JWST UNCOVER: Extremely Red and Compact Object at z phot ≃ 7.6 Triply Imaged by A2744
The Astrophysical Journal, 2023 Recent JWST/NIRCam imaging taken for the ultra-deep UNCOVER program reveals a very red dropout object at z _phot ≃ 7.6, triply imaged by the galaxy cluster A2744 ( z _d = 0.308).
Lukas J. Furtak +31 more
doaj +1 more source
The hard X-ray luminosity function of high-redshift (3 < z ≲ 5) active galactic nuclei [PDF]
, 2014 We present the hard-band (2-10 keV) X-ray luminosity function (HXLF) of 0.5-2 keV band selected active galactic nuclei (AGN) at high redshift. We have assembled a sample of 141 AGN at 3 = 23 to be 0.54 ± 0.05, with no strong dependence on luminosity ...
Comastri, A. +17 more
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