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Related papers: Revisiting the Unified Model of Active Galactic Nu…

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This Astro2020 white paper summarizes the unknowns of active galactic nuclei (AGN) physics that could be unveiled thanks to a new, space-born, ultraviolet spectropolarimeter. The unique capabilities of high energy polarimetry would help us…

High Energy Astrophysical Phenomena · Physics 2019-03-14 F. Marin , S. Charlot , B. Agís González , D. Sluse , D. Hutsemékers , A. Labiano , L. Grosset , C. Neiner , J. -C. Bouret

The differences among apparently diverse classes of AGN are mainly the result of viewing the central engine at different orientations, because dust, which absorbs and scatters the light, partially covers the central source, and because…

Astrophysics · Physics 2007-05-23 Beverley J. Wills

The paradigm for AGN unification is reviewed, in terms of its optical manifestation as obscuration in the equatorial plane and its radio manifestation as relativistic beaming of the jet emission. Within this paradigm, observed AGN…

Astrophysics · Physics 2007-05-23 C. Megan Urry

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

We present a study of the connection between black hole accretion, star formation, and galaxy morphology at z<=2.5. We focus on active galactic nuclei (AGNs) selected by their mid-IR power-law emission. By fitting optical to far-IR…

Observations made during the last ten years with the Chandra X-ray Observatory have shed much light on the cooling gas in the centers of clusters of galaxies and the role of active galactic nucleus (AGN) heating. Cooling of the hot…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-14 Elizabeth L. Blanton , T. E. Clarke , Craig L. Sarazin , Scott W. Randall , Brian R. McNamara

In this second research note of a series of two, we present the first near-infrared results we obtained when modeling Active Galactic Nuclei (AGN). Our first proceedings showed the comparison between the MontAGN and STOKES Monte Carlo…

Astrophysics of Galaxies · Physics 2016-10-18 F. Marin , L. Grosset , R. Goosmann , D. Gratadour , D. Rouan , Y. Clénet , D. Pelat , P. Andrea Rojas Lobos

The primary source of emission of active galactic nuclei (AGN), the accretion disk, is surrounded by an optically and geometrically thick dusty structure ("the so-called dusty torus"). The infrared radiation emitted by the dust is nothing…

Astrophysics of Galaxies · Physics 2017-01-13 Marko Stalevski , Claudio Ricci , Yoshihiro Ueda , Paulina Lira , Jacopo Fritz , Maarten Baes

Emission from active galactic nuclei (AGNs) is known to play an important role in the evolution of many galaxies including luminous and ultraluminous systems (U/LIRGs), as well as merging systems. However, the extent, duration, and exact…

We analyze observations obtained with the Chandra X-ray Observatory of bright Compton thick active galactic nuclei (AGNs), those with column densities in excess of 1.5 x 10^{24} cm^{-2} along the lines of sight. We therefore view the…

Astrophysics · Physics 2011-07-21 N. A. Levenson , T. M. Heckman , J. H. Krolik , K. A. Weaver , P. T. Zycki

The merger of two or more galaxies can enhance the inflow of material from galactic scales into the close environments of Active Galactic Nuclei (AGN), obscuring and feeding the supermassive black hole (SMBH). Both recent simulations and…

We used the CLUMPY torus models and a Bayesian approach to fit the infrared spectral energy distributions (SEDs) and ground-based high-angular resolution mid-infrared spectroscopy of 13 nearby Seyfert galaxies. This allowed us to put tight…

We estimate the abundance of Compton-thick (CT) active galactic nuclei (AGN) based on our joint model of X-ray and infrared backgrounds. At L_{rest 2-10 keV} > 10^42 erg/s, the CT AGN density predicted by our model is a few 10^-4 Mpc^-3…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Yong Shi , George Helou , Lee Armus

Two families of models of dusty tori in AGNs (moderately thick and extended versus very thick and compact) are tested against available observations. The confrontation suggests that the former class better explains the IR broad-band spectra…

Astrophysics · Physics 2009-10-30 Gian Luigi Granato , Luigi Danese , Alberto Franceschini

The spectrum of the hard X-ray background records the history of accretion processes integrated over the cosmic time. Several pieces of observational and theoretical evidence indicate that a significant fraction of the energy density is…

Astrophysics · Physics 2016-01-27 Andrea Comastri

The unification of active galactic nuclei (AGN) is a model that has been difficult to test due to the lack of knowledge on the intrinsic luminosities of the objects. We present a test were we probe the model by statistical investigation of…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-05 Beatriz Villarroel , Andreas Korn , Yoshiki Matsuoka

The study of the content, distribution and kinematics of interstellar gas is a key to understand the origin and maintenance of both starburst and nuclear (AGN) activity in galaxies. The processes involved in AGN fueling encompass a wide…

Astrophysics · Physics 2009-11-13 S. Garcia-Burillo , F. Combes , A. Usero , J. Gracia-Carpio

We use data from the Wide-Field Infrared Survey Explorer (WISE) to perform a statistical study on the mid-infrared (IR) properties of a large number ($\sim10^2$) of BL Lac objects --- low-luminosity Active Galactic Nuclei (AGN) with a jet…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Richard M. Plotkin , Scott F. Anderson , W. N. Brandt , Sera Markoff , Ohad Shemmer , Jianfeng Wu

We perform X-ray spectral analyses to derive characteristics (e.g., column density, X-ray luminosity) of $\approx$10,200 active galactic nuclei (AGNs) in the XMM-Spitzer Extragalactic Representative Volume Survey (XMM-SERVS), which was…

Recent observations of NGC 1068 and other AGN support the idea of a geometrically and optically thick dust torus surrounding the central supermassive black hole and accretion disk of AGN. In type 2 AGN, the torus is seen roughly edge-on,…

Astrophysics · Physics 2007-05-23 S. F. Hoenig , T. Beckert , K. Ohnaka , G. Weigelt