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Related papers: The dust covering factor in active galactic nuclei

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Infrared-faint radio sources (IFRSs) are believed to be a rare class of radio-loud active galactic nuclei (RL AGN) characterized by their high radio-to-infrared flux density ratios of up to several thousands. Previous studies have shown…

Astrophysics of Galaxies · Physics 2025-02-11 Yihang Zhang , Lulu Fan , Tao An , Jun Yang , Weibin Sun , Haoran Yu , Yunkun Han

We present numerical simulations of properties of a parsec-scale torus exposed to illumination by the central black hole in an active galaxy (AGN). Our physical model allows to investigate the balance between the formation of winds and…

Astrophysics of Galaxies · Physics 2016-03-23 Anton Dorodnitsyn , Tim Kallman , Daniel Proga

We discuss a clumpy model of obscuring dusty tori around AGN. Cloud-cloud collisions lead to an effective viscosity and a geometrically thick accretion disk, which has the required properties of a torus. Accretion in the combined…

Astrophysics · Physics 2016-08-30 Thomas Beckert , Wolfgang J. Duschl , Bernd Vollmer

We investigate the radial structure of active galactic nuclei (AGN) dusty tori by forward-modeling mid-infrared (MIR) spectra observed with JWST/MIRI-MRS for a sample of 25 AGN. We develop a physically motivated three dimensional radiative…

Astrophysics of Galaxies · Physics 2026-03-17 Ruiyu Pan , Arkaprabha Sarangi

We have developed a new dynamical model of the torus region in active galactic nucleus (AGN), using a three-dimensional radiation hydrodynamics algorithm. These new simulations have the specific aim to explore the role of radiatively-driven…

Astrophysics of Galaxies · Physics 2019-05-29 David Williamson , Marta Venanzi , Sebastian Hönig

The active galactic nucleus (AGN) phenomena results from a supermassive black hole accreting its surrounding gaseous and dusty material. The infrared (IR) regime provides most of the information to characterize the dusty structures that…

Astrophysics of Galaxies · Physics 2022-05-31 Jianwei Lyu , George Rieke

The dusty torus plays a vital role in unifying active galactic nuclei (AGNs). However, the physical structure of the torus remains largely unclear. Here we present a systematical investigation of the torus mid-infrared (MIR) spectroscopic…

High Energy Astrophysical Phenomena · Physics 2020-09-30 Jun Xu , Mouyuan Sun , Yongquan Xue , Junyao Li , Zhicheng He

We have combined the CLASXS Chandra survey in Lockman with the Spitzer SWIRE survey data to study the X-ray-infrared connection for AGN. The sample consists of 401 X-ray-sources, of which 306 are detected by Spitzer, and a further 257 AGN…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-02 Michael Rowan-Robinson , Ivan Valtchanov , Kirpal Nandra

In the unification scheme, narrow-lined (type 2) active galactic nuclei (AGN) are intrinsically similar to broad-lined (type 1) AGN with the exception that the line of sight to the broad emission line region and accretion disk is blocked by…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Yu Lu , Ting-Gui Wang , Xiao-Bo Dong , Hong-Yan Zhou

X-ray emission detection in a galaxy is one of the efficient tools for selecting Active Galactic Nuclei (AGNs). However, many X-ray-selected AGNs are not easily selected as AGNs by their optical emission. These galaxies, so-called optically…

Astrophysics of Galaxies · Physics 2022-03-31 Itsna K. Fitriana , Takashi Murayama

We investigated the emission of active galactic nuclei dusty tori in the infrared domain, with a focus on the 10 micron silicate feature. We modeled the dusty torus as a clumpy two-phase medium with high-density clumps and a low-density…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-14 Marko Stalevski , Jacopo Fritz , Maarten Baes , Theodoros Nakos , Luka C. Popovic

In Unification Models, Active Galactic Nuclei (AGN) are believed to be surrounded by an axisymmetric structure of dust and gas, which greatly influences their observed properties according to the direction from which they are observed. The…

Astrophysics · Physics 2009-11-11 E. Ibar , P. Lira

In order to understand the diversity of classes observed in active galactic nuclei (AGN), a geometrically and optically thick torus of gas and dust is required to obscure the central engine depending on the line of sight to the observer. We…

We investigate the infrared (IR) emission of high-redshift ($z\sim 6$), highly star-forming (${ {\rm SFR} > 100}$ $M_{\rm \odot} {\rm yr}^{-1}$) galaxies, with/without Active Galactic Nuclei (AGN), using a suite of cosmological simulations…

Astrophysics of Galaxies · Physics 2021-03-10 F. Di Mascia , S. Gallerani , C. Behrens , A. Pallottini , S. Carniani , A. Ferrara , P. Barai , F. Vito , T. Zana

Active Galactic Nuclei (AGN) produce a dominant fraction (~80%) of the Soft X-ray background (SXB) at photon energies 0.5<E<2 keV. If dust pervaded throughout the intergalactic medium, its scattering opacity would have produced diffuse…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Mark Dijkstra , Abraham Loeb

The luminous electromagnetic emission from distant active galactic nuclei (AGNs) including quasars is believed to be powered by accretion onto super-massive black holes (SMBHs). In the standard unification model for AGNs a dusty torus…

Astrophysics · Physics 2009-11-10 Shuang Nan Zhang

We explore a detailed model in which the active galactic nucleus (AGN) obscuration results from the extinction of AGN radiation in a global flow driven by the pressure of infrared radiation on dust grains. We assume that external…

High Energy Astrophysical Phenomena · Physics 2012-03-15 A. Dorodnitsyn , T. Kallman , G. S. Bisnovatyi-Kogan

We explore the origin of mid-infrared (mid-IR) dust extinction in all 20 nearby (z < 0.05) bona-fide Compton-thick (N_H > 1.5 x 10^24 cm^-2) AGN with hard energy (E > 10 keV) X-ray spectral measurements. We accurately measure the silicate…

Astrophysics of Galaxies · Physics 2015-06-05 A. D. Goulding , D. M. Alexander , F. E. Bauer , W. R. Forman , R. C. Hickox , C. Jones , J. R. Mullaney , M. Trichas

Spatially resolving the innermost torus in AGN is one of the main goals of its high-spatial-resolution studies. This could be done in the near-IR observations of Type 1 AGNs where we see directly the hottest dust grains in the torus. We…

Astrophysics · Physics 2009-11-13 Makoto Kishimoto , Sebastian F. Hoenig , Thomas Beckert , Gerd Weigelt

Heavily obscured Active Galactic Nuclei (AGN), especially Compton-thick sources with line-of-sight column density ($N_{\rm H,los}$) $>$ 10$^{24}$ cm$^{-2}$, are critical to understanding supermassive black hole (SMBH) growth and the origin…