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相关论文: Systematic Study of AGN Clumpy Tori with Broadband…

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Several authors have claimed that the less luminous active galactic nuclei (AGN) are not capable of sustaining the dusty torus structure. Thus, a gradual re-sizing of the torus is expected when the AGN luminosity decreases. Our aim is to…

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

Over ten mid-infrared (mid-IR) and X-ray models are currently attempting to describe the nuclear obscuring material of active galactic nuclei (AGNs), but many questions remain unresolved. This study aims to determine the physical parameters…

According to unified schemes of Active Galactic Nuclei (AGN), the central engine is surrounded by dusty, optically thick clouds in a toroidal structure. We have recently developed a formalism that for the first time takes proper account of…

天体物理学 · 物理学 2009-11-13 Maia Nenkova , Matthew M. Sirocky , Zeljko Ivezic , Moshe Elitzur

We fitted Spitzer/IRS ~2-35 um spectra of 26 luminous QSOs in attempt to define the main emission components. Our model has three major components: a clumpy torus, dusty narrow line region (NLR) clouds and a blackbody-like dust. The models…

宇宙学与河外天体物理 · 物理学 2011-02-11 Rivay Mor , Hagai Netzer , Moshe Elitzur

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

An integral part of the Unified Model for Active Galactic Nuclei (AGNs) is an axisymmetric obscuring medium, which is commonly depicted as a torus of gas and dust surrounding the central engine. However, a robust, dynamical model of the…

宇宙学与河外天体物理 · 物理学 2015-06-04 S. K. Keating , J. E. Everett , S. C. Gallagher , R. P. Deo

We describe a complete volume limited sample of nearby active galaxies selected by their 14-195keV luminosity, and outline its rationale for studying the mechanisms regulating gas inflow and outflow. We describe also a complementary sample…

Obscuration of the innermost parts of active galactic nuclei (AGN) is observed in the majority of the population both in the nearby universe and at high redshift. However, the nature of the structures causing obscuration, especially in…

高能天体物理现象 · 物理学 2021-09-07 M. Baloković , S. E. Cabral , L. Brenneman , C. M. Urry

Observations give strong support for the unification scheme of active galactic nuclei. Clumpiness of the toroidal obscuration is crucial for explaining the IR observations and has significance consequences for AGN classification: type 1 and…

天体物理学 · 物理学 2007-05-23 Moshe Elitzur

We present a statistical analysis of the properties of the obscuring material around active galactic nuclei (AGN). This study represents the first of its kind for an ultra-hard X-ray (14-195keV; Swift/BAT) volume-limited (DL<40 Mpc) sample…

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…

We present a unification model for a clumpy obscurer in active galactic nuclei (AGN) and investigate the properties of the resulting X-ray spectrum. Our model is constructed to reproduce the column density distribution of the AGN population…

高能天体物理现象 · 物理学 2019-09-04 Johannes Buchner , Murray Brightman , Kirpal Nandra , Robert Nikutta , Franz E. Bauer

In this paper, we try to explain the observed correlation between the covering factor (CF) of hot dust and the properties of active galactic nuclei (AGNs), e.g., the bolometric luminosity ($L_{\rm{bol}}$) and black hole mass…

星系天体物理 · 物理学 2015-12-09 Jian-Jian He , Yuan Liu , Shuang-Nan Zhang

In Unification Models, Active Galactic Nuclei (AGN) are believed to be surrounded by an axisymmetric structure of dust and gas, which greatly influences their observed properties according to the direction from which they are observed. The…

天体物理学 · 物理学 2009-11-11 E. Ibar , P. Lira

We have analyzed the broadband X-ray spectra of active galactic nuclei (AGNs) in two "non-merging" luminous infrared galaxies (LIRGs) UGC 2608 and NGC 5135, utilizing the data of NuSTAR, Suzaku, XMM-Newton, and Chandra. Applying the X-ray…

高能天体物理现象 · 物理学 2020-07-15 Satoshi Yamada , Yoshihiro Ueda , Atsushi Tanimoto , Saeko Oda , Masatoshi Imanishi , Yoshiki Toba , Claudio Ricci

We report a new sample of obscured active galactic nuclei (AGNs) selected from the XMM serendipitous source and AKARI point-source catalogs. We match X-ray sources with infrared (18 and 90 micron) sources located at |b|>10 deg to create a…

We present results from the fitting of infrared (IR) spectral energy distributions of 21 active galactic nuclei (AGN) with clumpy torus models. We compiled high spatial resolution ($\sim 0.3$--$0.7$ arcsec) mid-IR $N$-band spectroscopy,…

In modeling the X-ray spectra of active galactic nuclei (AGNs), the inclination angle is a parameter that can play an important role in analyzing the X-ray spectra of AGN, but it has never been studied in detail. We present a broadband…

星系天体物理 · 物理学 2020-05-13 X. Zhao , S. Marchesi , M. Ajello , M. balokovic , T. Fischer

According to theory, the torus of active galactic nuclei (AGN) is sustained from a wind coming off the accretion disk, and for low efficient AGN, it has been proposed that such structure disappears. However, the exact conditions for its…