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Related papers: Three-dimensional radiative transfer models of clu…

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Interferometric measurements in the mid-infrared have shown that the sizes of the warm dust distributions in active galactic nuclei are consistent with their scaling with the square root of their luminosity. We carry out a more detailed…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Konrad R. W. Tristram , Marc Schartmann

Optical/UV photons and even harder radiation components in galaxies are absorbed and scattered by dust and re-emitted at infrared wavelengths. For a better understanding of the obscured regions of the galaxies detailed models of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Ralf Siebenmorgen , Frank Heymann

We present 8-13 micron imaging and spectroscopy of 9 type 1 and 10 type 2 AGN obtained with the VLT/VISIR instrument at spatial resolution <100 pc. The emission from the host galaxy sources is resolved out in most cases. The silicate…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 S. F. Hoenig , M. Kishimoto , P. Gandhi , A. Smette , D. Asmus , W. Duschl , M. Polletta , G. Weigelt

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

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…

Substantial evidence points to dusty, geometrically thick tori obscuring the central engines of active galactic nuclei (AGNs), but so far no mechanism satisfactorily explains why cool dust in the torus remains in a puffy geometry.…

Astrophysics of Galaxies · Physics 2016-07-04 Chi-Ho Chan , Julian H. Krolik

Recently, the existence of geometrically thick dust structures in Active Galactic Nuclei (AGN) has been directly proven with the help of mid-infrared interferometry. The observations are consistent with a two-component model made up of a…

Astrophysics · Physics 2009-11-13 M. Schartmann , K. Meisenheimer , H. Klahr , M. Camenzind , S. Wolf , Th. Henning

We use mid-infrared spectroscopy of unobscured active galactic nuclei (AGNs) to reveal their native dusty environments. We concentrate on Seyfert 1 galaxies, observing a sample of 31 with the Infrared Spectrograph aboard the Spitzer Space…

Astrophysics of Galaxies · Physics 2010-01-15 G. D. Thompson , N. A. Levenson , S. A. Uddin , M. M. Sirocky

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…

Astrophysics of Galaxies · Physics 2017-09-22 Triana Almeyda , Andrew Robinson , Michael Richmond , Billy Vazquez , Robert Nikutta

We have developed the dynamical model of a clumpy torus in an active galactic nucleus (AGN) and compared to recent ALMA observations. We present $N$-body simulations of a torus in the field of a supermassive black hole (SMBH), made of up to…

Astrophysics of Galaxies · Physics 2021-02-25 E. Yu. Bannikova , A. V. Sergeyev , N. A. Akerman , P. P. Berczik , M. V. Ishchenko , M. Capaccioli , V. S. Akhmetov

Active galactic nuclei play a key role in the evolution of galaxies, but their inner workings and physical connection to the host are poorly understood due to a lack of angular resolution. Infrared interferometry makes it possible to…

In the last decades, several multiwavelength studies have been dedicated to exploring the properties of the obscuring material in active galactic nuclei (AGN). Various models have been developed to describe the structure and distribution of…

We present model simulations of time-variable infrared (IR) emission from dust as a consequence of variability of the incident radiation. For that we introduce a generalized treatment for temperature variations in a dusty environment, which…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Sebastian F. Hoenig , Makoto Kishimoto

Two-dimensional radiative transfer is employed to obtain the broad-band infrared spectrum of active galaxies. In the models we vary the geometry and size of the obscuring medium, the surface density, the opacity and the grain size…

Astrophysics · Physics 2009-11-07 I. M. van Bemmel , C. P. Dullemond

(Abridged) Infrared high-resolution imaging and interferometry have shown that the dust distribution is frequently elongated along the polar direction of an AGN. To explain these findings, we developed a model scenario for the inner ~30 pc…

Astrophysics of Galaxies · Physics 2018-08-15 B. Vollmer , M. Schartmann , L. Burtscher , F. Marin , S. Hoenig , R. Davies , R. Goosmann

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

Dust reprocesses the intrinsic radiation of active galactic nuclei (AGNs) to emerge at longer wavelengths. The observed mid-infrared (MIR) luminosity depends fundamentally on the luminosity of the central engine, but in detail it also…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 N. A. Levenson , J. T. Radomski , C. Packham , R. E. Mason , J. J. Schaefer , C. M. Telesco

We present mid-IR interferometric observations of 6 type 1 AGNs at multiple baseline lengths of 27--130m, reaching high angular resolutions up to lambda/B~0.02 arcseconds. For two of the targets, we have simultaneous near-IR interferometric…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Makoto Kishimoto , Sebastian F. Hoenig , Robert Antonucci , Florentin Millour , Konrad R. W. Tristram , Gerd Weigelt

The outer regions of AGN disks have temperatures similar to those of circumstellar disks, permitting dust condensation. Therefore, planet formation and growth could be active in these dust tori through similar mechanisms. We aim at…

Earth and Planetary Astrophysics · Physics 2026-05-20 Bhupendra Mishra , Wladimir Lyra , Barry McKernan , Mordecai-Mark Mac Low , K. E. Saavik Ford , Harrison E. Cook