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相关论文: AGN Dusty Tori: II. Observational Implications of …

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The size and structure of the dusty circumnuclear torus in active galactic nuclei (AGN) can be investigated by analyzing the temporal response of the torus's infrared (IR) dust emission to variations in the AGN ultraviolet/optical…

星系天体物理 · 物理学 2020-03-02 Triana Almeyda , Andrew Robinson , Michael Richmond , Robert Nikutta , Bryanne McDonough

We assume that dust near active galactic nuclei (AGN) is distributed in a torus-like geometry, which may be described by a clumpy medium or a homogeneous disk or as a combination of the two (i.e. a 2-phase medium). The dust particles…

星系天体物理 · 物理学 2015-11-11 Ralf Siebenmorgen , Frank Heymann , Andreas Efstathiou

Near-Eddington radiation from active galactic nuclei (AGNs) has significant dynamical influence on the surrounding dusty gas, plausibly furnishing AGNs with geometrically thick obscuration. We investigate this paradigm with radiative…

星系天体物理 · 物理学 2017-08-21 Chi-Ho Chan , Julian H. Krolik

Aims: We aim to find torus models that explain the observed high-resolution mid-infrared (MIR) measurements of active galactic nuclei (AGN). Our goal is to determine the general properties of the circumnuclear dusty environments. Methods:…

星系天体物理 · 物理学 2016-06-29 N. López-Gonzaga , W. Jaffe

Deep surveys of {\em Chandra} and {\em HST} (Hubble Space Telescope) show that active galactic nucleus (AGN) populations are changing with hard X-ray luminosities. This arises an interesting question whether the dusty torus is evolving with…

天体物理学 · 物理学 2009-11-11 J. -M. Wang , E. P. Zhang , B. Luo

Coronal-Line Forest Active Galactic Nuclei (CLiF AGN) are characterized by strong, high-ionization lines, which are in contrast to what is found in typical AGNs. Here, we carry out an infrared analysis aimed at understanding the spectral…

星系天体物理 · 物理学 2023-07-05 F. C. Cerqueira-Campos , A. Rodríguez-Ardila , S. Panda , R. Riffel , L. G. Dahmer-Hahn , M. Marinello

We report the detection of a 9.7 $\mu$m silicate dust absorption feature toward the Cygnus A nucleus. Its optical depth is, however, significantly smaller than that expected from the dust extinction toward the background $L$-band emission…

天体物理学 · 物理学 2009-10-31 Masatoshi Imanishi , Shiro Ueno

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…

星系天体物理 · 物理学 2017-01-18 Yanxia Xie , Aigen Li , Lei Hao

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…

天体物理学 · 物理学 2009-10-31 R. Maiolino , A. Marconi , E. Oliva

We use photometric and spectroscopic infrared observations obtained with the Spitzer Space Telescope of 12 radio-loud active galactic nuclei (AGN) to investigate the dust geometry. Our approach is to look at the change of the infrared…

宇宙学与河外天体物理 · 物理学 2015-05-19 Hermine Landt , Catherine L. Buchanan , Pauline Barmby

We present observational evidences that dust in the circumnuclear region of AGNs has different properties than in the Galactic diffuse interstellar medium. By comparing the reddening of optical and infrared broad lines and the X-ray…

天体物理学 · 物理学 2009-10-31 R. Maiolino , A. Marconi , M. Salvati , G. Risaliti , P. Severgnini , F. La Franca , L. Vanzi

We compare three different models of clumpy gas disk and show that the Circumnuclear Disk (CND) in the Galactic Center and a putative, geometrically thick, obscuring torus are best explained by a collisional model consisting of…

天体物理学 · 物理学 2009-11-10 B. Vollmer , T. Beckert , W. J. Duschl

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…

星系天体物理 · 物理学 2021-09-29 Christos Panagiotou , Roland Walter , Stephane Paltani

Dust torus plays the key role in determining active galactic nuclei (AGN) observational appearance. Here, the scenario of accretion regulated central dust torus is tested for the first time in the individual changing-look AGN (CLAGN) SDSS…

星系天体物理 · 物理学 2026-04-09 Zhang XueGuang

A growing body of evidence suggests that part of, if not all, scattering regions of active galactic nuclei (AGNs) are clumpy. Hence. in this paper, we run radiative transfer models in the optical/UV for a variety of AGN reprocessing regions…

高能天体物理现象 · 物理学 2015-05-06 F. Marin , R. W. Goosmann , C. M. Gaskell

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…

Context: We investigate mid-infrared and X-ray properties of the dusty torus invoked in the unification scenario for active galactic nuclei. Aims: We use the relation between mid IR and hard X-ray luminosities to constrain the geometry and…

天体物理学 · 物理学 2009-11-13 Hannes Horst , Poshak Gandhi , Alain Smette , Wolfgang J. Duschl

We combine near-to-mid-IR Spitzer data with shorter wavelength observations (optical to X-rays) to get insights on the properties of a sample of luminous, obscured Active Galactic Nuclei (AGN). We aim at modeling their broad-band Spectral…

宇宙学与河外天体物理 · 物理学 2015-05-18 F. Pozzi , C. Vignali , A. Comastri , E. Bellocchi , J. Fritz , C. Gruppioni , M. Mignoli , R. Maiolino , L. Pozzetti , M. Brusa , F. Fiore , G. Zamorani

We apply a new X-ray clumpy torus model called XCLUMPY (Tanimoto et al. 2019), where the clump distribution is assumed to be the same as in the infrared clumpy torus model (CLUMPY) by Nenkova et al. 2008, to the broadband X-ray spectra of…

高能天体物理现象 · 物理学 2019-05-01 Shoji Ogawa , Yoshihiro Ueda , Satoshi Yamada , Atsushi Tanimoto , Toshihiro Kawaguchi

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…