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Related papers: AGN dust tori at low and high luminosities

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In a companion paper, Maiolino et al. (2000) presented various observational evidences for "anomalous" dust properties in the circumnuclear region of AGNs and, in particular, the reduced E(B-V)/N_H and Av/N_H ratios, the absence of the…

Astrophysics · Physics 2009-10-31 R. Maiolino , A. Marconi , E. Oliva

We present the first direct imaging of what may be the thick torus in the active galactic nucleus (AGN) of the archetype powerful radio galaxy Cygnus A, using the Jansky Very Large Array (VLA) at 18 GHz to 48 GHz, with a resolution down to…

High Energy Astrophysical Phenomena · Physics 2019-07-17 C. L. Carilli , R. A. Perley , V. Dhawan , D. A. Perley

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,…

We present the optical narrow line ratios in an SDSS based sample of 3,175 broad Ha selected type 1 AGN, and explore their positions in the BPT diagrams as a function of the AGN and the host properties. We find the following: 1. The…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Jonathan Stern , Ari Laor

We examine the relative orientation of radio jets and dusty tori surrounding the AGN in powerful radio galaxies at z > 1. The radio core dominance R = P(20 GHz) /P(500 MHz) serves as an orientation indicator, measuring the ratio between the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 G. Drouart , C. De Breuck , J. Vernet , R. A. Laing , N. Seymour , D. Stern , M. Haas , E. A. Pier , B. Rocca-Volmerange

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

We present an optical variability analysis and comparison of the samples of Seyfert 1 and 2 galaxies, selected from the \textit{Swift} 9-month BAT catalog, using the light curves from Transiting Exoplanet Survey Satellite (TESS) and All-Sky…

At distances from the active galaxy nucleus (AGN) where the ambient temperature falls below ~1500-1800 K, dust is able to survive. It is thus possible to have a large dusty structure present which surrounds the AGN. This is the first of two…

Recent high angular resolution observations resolved for the first time the mid-infrared (MIR) structure of nearby active galactic nuclei (AGN). Surprisingly, they revealed that a major fraction of their MIR emission comes from the polar…

Astrophysics of Galaxies · Physics 2017-08-30 Marko Stalevski , Daniel Asmus , Konrad R. W. Tristram

Accreting supermassive black holes (SMBHs) located at the center of galaxies are typically surrounded by large quantities of gas and dust. The structure and evolution of this circumnuclear material can be studied at different wavelengths,…

In this paper we report the results of an X-ray monitoring campaign on the heavily obscured Seyfert galaxy Markarian 3 carried out between the fall of 2014 and the spring of 2015 with NuSTAR, Suzaku and XMM-Newton. The hard X-ray spectrum…

The inner structure of AGNs is expected to change below a certain luminosity limit. The big blue bump, footprint of the accretion disk, is absent for the majority of low-luminosity AGNs (LLAGNs). Moreover, recent simulations suggest that…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 J. A. Fernández-Ontiveros , M. A. Prieto , J. A. Acosta-Pulido , M. Montes

We investigate the Eddington ratio distribution of X-ray selected broad-line active galactic nuclei (AGN) in the redshift range 1.0<z<2.2, where the number density of AGNs peaks. Combining the optical and Subaru/FMOS near-infrared…

Astrophysics of Galaxies · Physics 2016-01-20 Hyewon Suh , Guenther Hasinger , Charles Steinhardt , John D. Silverman , Malte Schramm

An optically and geometrically thick torus obscures the central engine of Active Galactic Nuclei (AGN) from some lines of sight. From a magnetohydrodynamical framework, the torus can be considered to be a particular region of clouds…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-21 E. Lopez-Rodriguez , C. Packham , S. Young , M. Elitzur , N. A. Levenson , R. E. Mason , C. Ramos Almeida , A. Alonso-Herrero , T. J. Jones , E. Perlman

An interesting feature in active galactic nuclei (AGN) accreting at low rate is the weakness of the reflection features in their X-ray spectra, which can result from the gradual disappearance of the torus with decreasing accretion rates. It…

Changing-look active galactic nuclei (CLAGNs) are known to change their spectral type between 1 and 2 (changing-state) or change their absorption between Compton-thick and Compton-thin (changing-obscuration) on timescales of years or less.…

High Energy Astrophysical Phenomena · Physics 2025-01-17 Bing Lyu , Zhen Yan , Xue-bing Wu , Qingwen Wu , Wenfei Yu , Hao Liu

Temporal asymmetry in the flux variability of active galactic nuclei (AGNs) offers key insights into the physical mechanisms driving AGN variability. In this study, we investigated the variability of the torus by analyzing temporal…

Astrophysics of Galaxies · Physics 2026-01-05 Suyeon Son , Minjin Kim , Luis C. Ho

Dust plays an essential role in the unification theory of active galactic nuclei (AGNs). This review summarizes our current understanding of the extinction and infrared emission properties of the circumnuclear dust in AGNs as well as the…

Astrophysics · Physics 2008-09-01 Aigen Li

We construct a new sample of 32 obscured active galactic nuclei (AGNs) selected from the Second XMM-Newton Serendipitous Source Catalogue to investigate their multiwavelength properties in relation to the "scattering fraction", the ratio of…

One of the most puzzling properties of the high-redshift AGN population recently discovered by JWST, including both broad-line and narrow-line sources, is their X-ray weakness. With very few exceptions, and regardless of the optical…

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