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This work focuses on the properties of dusty tori in active galactic nuclei (AGN) derived from the comparison of SDSS type 1 quasars with mid-Infrared (MIR) counterparts and a new, detailed torus model. The infrared data were taken by the…

天体物理学 · 物理学 2007-05-23 Evanthia Hatziminaoglou , the SWIRE Team

To test the dust torus model for active galactic nuclei directly, we study the extent and morphology of the nuclear dust distribution in the Circinus galaxy using high resolution interferometric observations in the mid-infrared with the…

Unified schemes of active galactic nuclei (AGN) require an obscuring dusty torus around the central engine. The compact sizes (only a few pc) determined in recent high-resolution observations require that the obscuring matter be clumpy and…

天体物理学 · 物理学 2011-02-11 Moshe Elitzur , Isaac Shlosman

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

Present AGN and starburst models aiming to account for the observed infrared SEDs consider a physical description of the dust and a solution of the radiative transfer problem. MIR spectra obtained at different spatial scales (SST-IRS, ISO…

天体物理学 · 物理学 2007-05-23 Ralf Siebenmorgen

The infrared is a key wavelength regime for probing the dusty, obscured nuclear regions of active galaxies. We present results from an infrared study of 87 nearby Seyfert galaxies using the Spitzer Space Telescope and ground-based…

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

The obscuring circumnuclear torus of dusty molecular gas is one of the major components of active galactic nuclei (AGN). The torus can be studied by analyzing the time response of its infrared (IR) dust emission to variations in the AGN…

星系天体物理 · 物理学 2017-09-22 Triana Almeyda , Andrew Robinson , Michael Richmond , Billy Vazquez , Robert Nikutta

The range of currently proposed active galactic nucleus (AGN) far-infrared templates results in uncertainties in retrieving host galaxy information from infrared observations and also undermines constraints on the outer part of the AGN…

星系天体物理 · 物理学 2017-05-26 Jianwei Lyu , George H. Rieke

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…

宇宙学与河外天体物理 · 物理学 2015-06-17 Yong Shi , George Helou , Lee Armus

We present an analysis of a sample of 69 local obscured Swift/Burst Alert Telescope active galactic nuclei (AGNs) with X-ray spectra from NuSTAR and infrared (IR) spectral energy distributions from Herschel and WISE. We combine this X-ray…

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

Deep X-ray surveys by Chandra and XMM-Newton have resolved about 80% of the 2-10 keV cosmic extragalactic X-ray background (CXRB) into point sources, the majority of which are obscured AGN. The obscuration might be connected to processes…

天体物理学 · 物理学 2008-11-26 D. R. Ballantyne , Y. Shi , G. H. Rieke , J. L. Donley , C. Papovich , J. R. Rigby

Fits the infrared spectra from the nuclear regions of AGN can place constraints on the dust properties, distribution, and geometry by comparison with models. However, none of the currently available models fully describe the observations of…

This letter presents a revised radiative transfer model for the infrared (IR) emission of active galactic nuclei (AGN). While current models assume that the IR is emitted from a dusty torus in the equatorial plane of the AGN, spatially…

星系天体物理 · 物理学 2017-04-05 Sebastian F. Hönig , Makoto Kishimoto

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…

The putative dusty torus is a key ingredient of the unification scheme of active galactic nuclei (AGN), but its origin remains a mystery. Here we put forward a new physical model to explain how a large number of small dusty gas clumps form…

星系天体物理 · 物理学 2026-03-09 Xinwu Cao , Renyue Cen , Qingwen Wu , Jiancheng Wu

X-ray surveys have revealed a new class of active galactic nuclei (AGN) with a very low observed fraction of scattered soft X-rays, f_scat < 0.5%. Based on X-ray modeling these "X-ray new-type", or low observed X-ray scattering…

星系天体物理 · 物理学 2015-06-17 S. F. Hoenig , P. Gandhi , D. Asmus , R. F. Mushotzky , R. Antonucci , Y. Ueda , K. Ichikawa

We investigate the infrared contribution from supermassive black hole activity versus host galaxy emission in the mid to far-infrared (IR) spectrum for a large sample of X-ray bright active galactic nuclei (AGN) residing in dusty,…

星系天体物理 · 物理学 2019-07-02 Arianna Brown , Hooshang Nayyeri , Asantha Cooray , Jingzhe Ma , Ryan C. Hickox , Mojegan Azadi

Cosmic dust is a key tracer of structure formation and evolution in the universe. In active galactic nuclei (AGN) the origin and role of dust are uncertain. Here, we have studied dust in the X-ray bright and reddened type-1 quasar IC 4329A,…

高能天体物理现象 · 物理学 2018-11-14 Missagh Mehdipour , Elisa Costantini