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相关论文: The AGN Obscuring Torus -- End of the "Doughnut" P…

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The obscuring structure surrounding active galactic nuclei (AGN) can be explained as a dust and gas flow cycle that fundamentally connects the AGN with their host galaxies. This structure is believed to be associated with dusty winds driven…

The basic unified model of active galactic nuclei (AGN) invokes an anisotropic obscuring structure, usually referred to as a torus, to explain AGN obscuration as an angle-dependent effect. We present a new grid of X-ray spectral templates…

高能天体物理现象 · 物理学 2018-02-21 M. Baloković , M. Brightman , F. A. Harrison , A. Comastri , C. Ricci , J. Buchner , P. Gandhi , D. Farrah , D. Stern

Precise mechanisms by which Active Galactic Nuclei (AGN) receive their gaseous fuel is still a mystery. Here I draw attention to the extra ordinary star formation event that took place in the central ~ 0.5 parsec of our Galaxy. The most…

天体物理学 · 物理学 2007-05-23 Sergei Nayakshin

Winds launched at the scale of the accretion disc or dusty torus in Active Galactic Nuclei (AGN) are thought to drive energy-conserving outflows that shape galaxy evolution. The key signature of such outflows, the presence of a hot ($T…

星系天体物理 · 物理学 2026-02-06 Ivan Almeida , Tiago Costa , Chris M. Harrison , Samuel R. Ward

The "torus" obscurer of Active Galactic Nuclei (AGN) is poorly understood in terms of its density, substructure and physical mechanisms. Large X-ray surveys provide model boundary constraints, for both Compton-thin and Compton-thick levels…

高能天体物理现象 · 物理学 2017-01-11 Johannes Buchner , Franz E. Bauer

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

The presence of obscuring material (or a dusty `torus') in active galactic nuclei (AGN) is central to the unification model for AGN. Two models, the multi-population model for radio sources and the receding torus model, are capable of…

天体物理学 · 物理学 2009-11-10 T. G. Arshakian

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…

The "torus" is the central element of the most popular theory unifying various classes of AGNs, but it is usually described as "putative" because it has not been imaged yet. Since it is too small to be resolved with single-dish telescopes,…

We present the distributions of geometrical covering factors of active galactic nuclei (AGNs) dusty tori (f2) using an X-ray selected complete sample of 227 AGN drawn from the Bright Ultra-hard XMM-Newton Survey. The AGN have z from 0.05 to…

In some AGN, nuclear dust lanes connected to kpc-scale dust structures provide all the extinction required to obscure the nucleus, challenging the role of the dusty torus proposed by the Unified Model. In this letter we show the pc-scale…

星系天体物理 · 物理学 2016-01-13 M. Mezcua , M. A. Prieto , J. A. Fernández-Ontiveros , K. R. W. Tristram

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…

(abridged) It is generally assumed that the distribution of dust on parsec scales forms a geometrically- and optically-thick entity in the equatorial plane around the accretion disk and broad-line region - dubbed "dust torus" - that emits…

Obscured AGNs provide an opportunity to study the material surrounding the central engine. Geometric and physical constraints on the absorber can be deduced from the reprocessed AGN emission. In particular, the obscuring gas may reprocess…

高能天体物理现象 · 物理学 2015-06-23 Raj Gohil , David R. Ballantyne

Heavily obscured Active Galactic Nuclei (AGN), especially Compton-thick sources with line-of-sight column density ($N_{\rm H,los}$) $>$ 10$^{24}$ cm$^{-2}$, are critical to understanding supermassive black hole (SMBH) growth and the origin…

The presence of an obscuring torus at pc-scale distances from the central black hole is the main ingredient for the Unified Model of Active Galactic Nuclei (AGN), as obscured sources are thought to be seen through this structure. However,…

We propose a new method to explore the candidate super-Eddington active galactic nuclei (AGNs). We examine the properties of infrared (IR) emission from the inner edge of the dusty torus in AGNs, which are powered by super- or sub-Eddington…

宇宙学与河外天体物理 · 物理学 2015-05-28 Nozomu Kawakatu , Ken Ohsuga

The inevitable spread in properties of the toroidal obscuration of active galactic nuclei (AGNs) invalidates the widespread notion that type 1 and 2 AGNs are intrinsically the same objects, drawn randomly from the distribution of torus…

宇宙学与河外天体物理 · 物理学 2015-06-04 Moshe Elitzur

Recent VLT SINFONI observations of the close environments (~30pc) of nearby AGNs have shown that thick gas tori and starbursts with ages between 10 and 150Myr are frequently found. By applying these observations to a previously established…

天体物理学 · 物理学 2009-11-13 B. Vollmer , T. Beckert , R. Davies

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