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Related papers: The dust covering factor in active galactic nuclei

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Several models of nuclear dust in active galactic nuclei (AGN) have been presented in the literature to determine its physical and geometrical properties, usually assuming the dust density distribution as the main aspect producing…

The nature of the putative torus and the outer geometry of active galactic nuclei (AGN) are still rather unknown and the subject of active research. Improving our understanding of them is crucial for developing a physical picture for the…

Astrophysics of Galaxies · Physics 2021-09-29 Christos Panagiotou , Roland Walter , Stephane Paltani

Substantial evidence points to dusty, geometrically thick tori obscuring the central engines of active galactic nuclei (AGNs), but so far no mechanism satisfactorily explains why cool dust in the torus remains in a puffy geometry.…

Astrophysics of Galaxies · Physics 2016-07-04 Chi-Ho Chan , Julian H. Krolik

The "torus" obscurer of Active Galactic Nuclei (AGN) is poorly understood in terms of its density, substructure and physical mechanisms. Large X-ray surveys provide model boundary constraints, for both Compton-thin and Compton-thick levels…

High Energy Astrophysical Phenomena · Physics 2017-01-11 Johannes Buchner , Franz E. Bauer

We analyze the link between active galactic nuclei (AGN) and mid-infrared flux using dust radiative transfer calculations of starbursts realized in hydrodynamical simulations. Focusing on the effects of galaxy dust, we evaluate diagnostics…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-12 Gregory F. Snyder , Christopher C. Hayward , Anna Sajina , Patrik Jonsson , Thomas J. Cox , Lars Hernquist , Philip F. Hopkins , Lin Yan

An accretion disk in an Active Galactic Nucleus (AGN) harbors and shields dust from external illumination: at the mid-plane of the disk around a $M_{{\rm BH}}=10^{7}M_{\odot}$ black hole, dust can exist at $0.1$pc from the black hole,…

Astrophysics of Galaxies · Physics 2021-04-07 Anton Dorodnitsyn , Tim Kallman

We derive the properties of dusty tori in Active Galactic Nuclei (AGN) from the comparison of observed Spectral Energy Distributions (SEDs) of SDSS quasars and a precomputed grid of torus models. The observed SEDs comprise SDSS photometry,…

The unification theory of active galactic nuclei (AGNs) hypothesizes that all AGNs are surrounded by an anisotropic dust torus and are essentially the same objects but viewed from different angles. However, little is known about the dust…

Astrophysics of Galaxies · Physics 2017-01-18 Yanxia Xie , Aigen Li , Lei Hao

Weak emission-line active galactic nuclei (WLAGNs) are radio-quiet active galactic nuclei (AGNs) that have nearly featureless optical spectra. We investigate the ultraviolet to mid-infrared spectral energy distributions of 73 WLAGNs…

Astrophysics of Galaxies · Physics 2016-09-20 Xudong Zhang , Yuan Liu

Radiation pressure-driven outflows from luminous accreting supermassive black holes are an important part of active galactic nucleus (AGN) feedback. The effective Eddington limit, based on absorption of radiation by dust, not electron…

Astrophysics of Galaxies · Physics 2022-11-16 N. Arakawa , A. C. Fabian , G. J. Ferland , W. Ishibashi

According to recent models, the accretion disk and black hole in active galactic nuclei are surrounded by a clumpy torus. We investigate the NIR flux variation of the torus in response to a UV flash for various geometries. Anisotropic…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Toshihiro Kawaguchi , Masao Mori

We present the results of a systematic, broadband X-ray spectral analysis of nearby active galactic nuclei (AGNs) with the X-ray clumpy torus model (XCLUMPY; Tanimoto et al. 2019). By adding 16 AGNs newly analyzed in this paper, we study…

High Energy Astrophysical Phenomena · Physics 2021-01-20 Shoji Ogawa , Yoshihiro Ueda , Atsushi Tanimoto , Satoshi Yamada

Spectral energy distribution (SED) fitting is one of most commonly used techniques to study the dust properties in Active Galactic Nuclei (AGN). Works implementing this technique commonly use radiative transfer models that assume a variety…

We investigate models for the power supply and broad-band spectral energy distribution (SED) of hyperluminous IR galaxies, recently discovered at high redshifts, in terms of the emission from an active nucleus embedded in a torus-like dusty…

Astrophysics · Physics 2009-10-28 Gian Luigi Granato , Luigi Danese , Alberto Franceschini

Many Active Galactic Nuclei (AGN) are surrounded by gas which absorbs the radiation produced by accretion onto the central black hole and obscures the nucleus from direct view. The dust component of the gas greatly enhances the effect of…

Astrophysics · Physics 2009-11-13 A. C. Fabian , R. V. Vasudevan , P. Gandhi

The torus concept as an essential structural component of active galactic nuclei (AGN) is generally accepted. Here, the situation is discussed when the torus "twisting" by the radiation or wind transforms it into a dipole toroidal vortex…

Astrophysics · Physics 2009-11-13 Elena Yu. Bannikova , Victor M. Kontorovich

The detection of dusty winds dominating the infrared emission of AGN on parsec scales has revealed the limitations of traditional radiative transfer models based on a toroidal distribution of dusty gas. A new, more complex, dynamical…

Astrophysics of Galaxies · Physics 2020-07-28 Marta Venanzi , Sebastian Hönig , David Williamson

We report the discovery of two sources at z=3.867 and z=3.427 that exhibit powerful starburst and AGN activities. They benefit from data from radio to X rays from the CFHTLS-D1/SWIRE/XMDS surveys. Follow-up optical and near-infrared…

The obscuring structure surrounding active galactic nuclei (AGN) can be explained as a dust and gas flow cycle that fundamentally connects the AGN with their host galaxies. This structure is believed to be associated with dusty winds driven…

Over ten mid-infrared (mid-IR) and X-ray models are currently attempting to describe the nuclear obscuring material of active galactic nuclei (AGNs), but many questions remain unresolved. This study aims to determine the physical parameters…

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