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相关论文: AGN Dusty Tori: I. Handling of Clumpy Media

200 篇论文

A high density of massive dark objects (MDOs), probably supermassive black holes, in the centres of nearby galaxies has been inferred from recent observations. There are various indications that much of the accretion responsible for…

天体物理学 · 物理学 2015-06-24 Neil Trentham , A. W. Blain

Dust emission, an important diagnostic of star formation and ISM mass throughout the Universe, can be powered by sources unrelated to ongoing star formation. In the framework of the DustPedia project we have set out to disentangle the…

In the framework of a systematic ALMA study of IR-selected main-sequence and starburst galaxies at z~1-1.7 at typical ~1" resolution, we report on the effects of mid-IR- and X-ray-detected active galactic nuclei (AGN) on the reservoirs and…

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…

We construct an X-ray spectral model for the clumpy torus in an active galactic nucleus (AGN) using Geant4, which includes the physical processes of the photoelectric effect, Compton scattering, Rayleigh scattering, $\gamma$ conversion,…

高能天体物理现象 · 物理学 2015-06-19 Yuan Liu , Xiaobo Li

We present 8-13 micron imaging and spectroscopy of 9 type 1 and 10 type 2 AGN obtained with the VLT/VISIR instrument at spatial resolution <100 pc. The emission from the host galaxy sources is resolved out in most cases. The silicate…

宇宙学与河外天体物理 · 物理学 2015-05-18 S. F. Hoenig , M. Kishimoto , P. Gandhi , A. Smette , D. Asmus , W. Duschl , M. Polletta , G. Weigelt

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…

天体物理学 · 物理学 2008-09-01 Aigen Li

This is the second in a series of papers devoted to explore a set of six dusty models of active galactic nuclei (AGN) with available spectral energy distributions (SEDs). These models are the smooth torus by Fritz et al. (2006), the clumpy…

Present AGN models aiming to account for the observed infrared SEDs consider a physical description of the dust and a solution of the radiative transfer problem. Mid infrared spectra obtained at different spatial scales are presented. They…

天体物理学 · 物理学 2009-11-10 Ralf Siebenmorgen , Andreas Efstathiou

We studied the physical parameters of a sample comprising of all Spitzer/IRS public spectra of Seyfert galaxies in the mid-infrared (5.2-38$\mu$m range) under the active galactic nuclei (AGN) unified model. We compare the observed spectra…

The unified model of active galactic nuclei (AGN) claims that the properties of AGN depend on the viewing angle of the observer with respect to a toroidal distribution of dust surrounding the nucleus. Both the mid-infrared (MIR) attenuation…

It is widely assumed that long-wavelength infrared (IR) emission from cold dust (T~20-40K) is a reliable tracer of star formation even in the presence of a bright active galactic nucleus (AGN). Based on radiative transfer (RT) models of…

This study investigates the properties of two gas structures of X-ray selected active galactic nuclei (AGNs), that is, dusty and dust-free gas components, by separating them with the line-of-sight dust extinction ($A_V$) and the neutral gas…

These proceedings are based on an invited review talk at the 7th Meeting on Cosmic Dust. The scope of the meeting was broad, covering dust-related topics in areas from comets to debris disks and high-redshift galaxies. This is therefore…

星系天体物理 · 物理学 2015-10-14 Rachel E. Mason

One of the key ingredients of the Unified Model of Active Galactic Nuclei (AGN) is the presence of a torus-like optically thick medium composed by dust and gas around the putative supermassive black hole. However, the structure, size and…

高能天体物理现象 · 物理学 2015-05-12 L. Ballo , P. Severgnini , A. Moretti , R. Della Ceca , S. Andreon , A. Caccianiga , V. Braito , S. Campana , C. Vignali

We propose a classification scheme for the circumnuclear medium of AGNs based on their location in the A_V - N_H plane (related to dust absorption and gas absorption, respectively). We present evidence that the A_V/N_H ratio is often lower…

天体物理学 · 物理学 2007-05-23 R. Gilli , G. Risaliti , P. Severgnini , R. Maiolino , A. Marconi , M. Salvati

The torus in Active Galactic Nuclei (AGN) is a complex dynamical structure of gas and dust. It is thought to be composed of an equatorial dusty disk and a polar dusty wind launched by radiation pressure. However, this picture is based on…

星系天体物理 · 物理学 2026-01-12 Farin Drewes , James H. Leftley , Sebastian F. Hönig , Konrad W. Tristram , Makoto Kishimoto

The presence of absorbing gas around the central engine of Active Galactic Nuclei (AGN) is a common feature of these objects. Recent work has looked at the effect of the dust component of the gas, and how it enhances radiation pressure such…

宇宙学与河外天体物理 · 物理学 2015-05-19 S. I. Raimundo , A. C. Fabian , F. E. Bauer , D. M. Alexander , W. N. Brandt , B. Luo , R. V. Vasudevan , Y. Q. Xue

Observations give strong support for the unification scheme of active galactic nuclei. The scheme is premised on toroidal obscuration of the central engine by dusty clouds that are individually very optically thick. These lectures summarize…

天体物理学 · 物理学 2009-11-13 Moshe Elitzur

We explore the gas dynamics near the dust sublimation radius of active galactic nucleus (AGN). For the purpose, we perform axisymmetric radiation hydrodynamic simulations of a dusty gas disk of radius $\approx 1\,\mathrm{pc}$ around a…

高能天体物理现象 · 物理学 2016-04-27 Daisuke Namekata , Masayuki Umemura