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Related papers: The AGN dusty torus as a clumpy two-phase medium: …

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A cornerstone of AGN unification schemes is the presence of an optically and geometrically thick dust torus. It provides the obscuration to explain the difference between type 1 and type 2 AGN. We investigate the influence of the dust…

Astrophysics · Physics 2007-09-24 Sebastian F. Hoenig , Thomas Beckert

A three dimensional parallel Monte Carlo (MC) dust radiative transfer code is presented. To overcome the huge computing time requirements of MC treatments, the computational power of vectorized hardware is used, utilizing either multi-core…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Frank Heymann , Ralf Siebenmorgen

We construct a generic X-ray spectral model for the reflection component from the clumpy torus and dusty gas in the polar region (polar dusty gas) in an active galactic nucleus (AGN), designated as Inclusive spectral energy distribution…

High Energy Astrophysical Phenomena · Physics 2025-12-25 Kanta Fujiwara , Yoshihiro Ueda , Shoji Ogawa , Yuya Nakatani , Ryosuke Uematsu

We investigated the gravitational microlensing of active galactic nucleus dusty tori in the case of lensed quasars in the infrared domain. The dusty torus is modeled as a clumpy two-phase medium. To obtain spectral energy distributions and…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-04 Marko Stalevski , Predrag Jovanović , Luka Č. Popović , Maarten Baes

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…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 S. K. Keating , J. E. Everett , S. C. Gallagher , R. P. Deo

The geometry of the dust distribution within the inner regions of Active Galactic Nuclei (AGN) is still a debated issue and relates directly with the AGN unified scheme. Traditionally, models discussed in the literature assume one of two…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 A. Feltre , E. Hatziminaoglou , J. Fritz , A. Franceschini

The primary source of emission of active galactic nuclei (AGN), the accretion disk, is surrounded by an optically and geometrically thick dusty structure ("the so-called dusty torus"). The infrared radiation emitted by the dust is nothing…

Astrophysics of Galaxies · Physics 2017-01-13 Marko Stalevski , Claudio Ricci , Yoshihiro Ueda , Paulina Lira , Jacopo Fritz , Maarten Baes

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…

Astrophysics of Galaxies · Physics 2017-04-05 Sebastian F. Hönig , Makoto Kishimoto

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…

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…

Astrophysics · Physics 2009-11-10 Ralf Siebenmorgen , Andreas Efstathiou

We explore physically self-consistent models of dusty molecular tori in Active Galactic Nuclei (AGN) with the goal of interpreting VLTI observations and fitting high resolution mid-IR spectral energy distributions (SEDs). The input dust…

The AGN-heated dust distribution (the "torus") is increasingly recognized not only as the absorber required in unifying models, but as a tracer for the reservoir that feeds the nuclear Super-Massive Black Hole. Yet, even its most basic…

A Monte Carlo model of radiative transfer in multi-phase dusty media is applied to the situation of stars and clumpy dust in a sphere or a disk. The distribution of escaping and absorbed photons are shown for various filling factors and…

Astrophysics · Physics 2007-05-23 Frank Varosi , Eli Dwek

We discuss the question whether the matter in dusty tori around active galactic nuclei has a smooth or a clumpy structure. Nenkova, Ivezic & Elitzur (2002) have argued that the lack of emission feature in the SEDs of type 1 AGN galaxies…

Astrophysics · Physics 2009-11-10 C. P. Dullemond , I. M. van Bemmel

Spectral energy distribution (SED) fitting is one of most commonly used techniques to study the dust properties in Active Galactic Nuclei (AGN). Works implementing this technique commonly use radiative transfer models that assume a variety…

We discuss a clumpy model of obscuring dusty tori around AGN. Cloud-cloud collisions lead to an effective viscosity and a geometrically thick accretion disk, which has the required properties of a torus. Accretion in the combined…

Astrophysics · Physics 2016-08-30 Thomas Beckert , Wolfgang J. Duschl , Bernd Vollmer

The detection of dusty winds dominating the infrared emission of AGN on parsec scales has revealed the limitations of traditional radiative transfer models based on a toroidal distribution of dusty gas. A new, more complex, dynamical…

Astrophysics of Galaxies · Physics 2020-07-28 Marta Venanzi , Sebastian Hönig , David Williamson

We present new calculations of the CAT3D clumpy torus models, which now include a more physical dust sublimation model as well as AGN anisotropic emission. These new models allow graphite grains to persist at temperatures higher than the…

Cold gas and dust reprocess the X-ray emission of active galactic nuclei (AGN), producing spectro-polarimetric features in the X-ray band. The recent launch of IXPE allows for observations of this X-ray polarisation signal, encoding unique…

High Energy Astrophysical Phenomena · Physics 2024-09-06 Bert Vander Meulen , Peter Camps , Djordje Savic , Maarten Baes , Giorgio Matt , Marko Stalevski

Thanks to ground-based infrared and sub-mm observations the study of the dusty torus of nearby AGN has greatly advanced in the last years. With the aim of further investigating the nuclear mid-infrared emission of the archetypal Seyfert 2…