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Related papers: AGN Dusty Tori as a Clumpy Two-Phase Medium: The 1…

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We present Monte Carlo radiative transfer simulations for spiral galaxies modelled as a stellar disk and a two-phase clumpy dust distribution. We divide the volume occupied by the dust into a three-dimensional grid and assign each cell a…

Astrophysics · Physics 2009-10-31 Simone Bianchi , Andrea Ferrara , Jon Davies , Paul Alton

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…

A geometrically thick dusty torus in NGC 1068 has been unambiguously resolved by an infrared interferometry telescope. This implies clouds composing the dusty torus are undergoing supersonic collisions with each other. We show that the…

Astrophysics · Physics 2009-11-10 Jian-Min Wang

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 present environmental dependence of dusty star forming activity in and around the cluster RXJ1716.4+6708 at z=0.81 based on wide-field and multi-wavelength observations with Suprime-Cam on the Subaru telescope and IRC onboard the AKARI…

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…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Yong Shi , George Helou , Lee Armus

We report the detection and successful modeling of the unusual 9.7\mum Si--O stretching silicate emission feature in the type 1 (i.e. face-on) LINER nucleus of M81. Using the Infrared Spectrograph (IRS) instrument on Spitzer, we determine…

Astrophysics of Galaxies · Physics 2015-05-18 Howard A. Smith , Aigen Li , M. P. Li , M. Koehler , M. L. N. Ashby , G. Fazio , J-S Huang , M. Marengo , Z. Wang , S. Willner , A. Zezas , L. Spinoglio , Y. L. Wu

The central region of NGC 1068 is one of the closest and most studied Active Galactic Nucleus. It is known to be of type 2, meaning that its accretion disk is obscured by a large amount of dust and gas. The main properties of the obscuring…

Dusty tori have been suggested to play a crucial role in determining the physical characteristics of active galactic nuclei (AGN), but investigation of their properties has stalled for lack of high resolution mid-IR imaging. Recently, a…

The feedback by active galactic nuclei (AGNs) is significant for the formation and evolution of galaxies. It has been realized that the radiative pressure feedback could be an efficient mechanism due to the existence of dust. In this…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Yuan Liu , Shuang Nan Zhang

We present the first Spitzer Infrared Spectrograph (IRS; The IRS was a collaborative venture between Cornell University and Ball Aerospace Corporation funded by NASA through the Jet Propulsion Laboratory and the Ames Research Center.)…

In this paper we study the effects of inclusions and porosities on the emission properties of silicate grains and compare the model curves with the observed infrared emission from circumstellar dust. We calculate the absorption efficiency…

Solar and Stellar Astrophysics · Physics 2015-03-17 D. B. Vaidya , Ranjan Gupta

The first detection of the silicate absorption feature in AGNs was made at 9.7 micrometer for the prototypical Seyfert 2 galaxy NGC 1068 over 30 years ago, indicating the presence of a large column of silicate dust in the line-of-sight to…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Melanie Koehler , Aigen Li

It is widely assumed that long-wavelength infrared (IR) emission from cold dust (T~20-40K) is a reliable tracer of star formation even in the presence of a bright active galactic nucleus (AGN). Based on radiative transfer (RT) models of…

Most of the optically classified low ionisation narrow emission-line regions (LINERs) nuclei host an active galactic nuclei (AGN). However, how they fit into the unified model (UM) of AGN is still an open question. The aims of this work are…

We investigate the circumstellar dust properties of the oxygen-rich bipolar proto-planetary nebula IRAS 18276-1431 by means of two-dimensional radiative transfer simulations of the circumstellar dust shell. The model geometry is assumed to…

Solar and Stellar Astrophysics · Physics 2015-06-12 K. Murakawa , H. Izumiura , R. D. Oudmaijer , L. T. Maud

We investigate models for the power supply and broad-band spectral energy distribution (SED) of hyperluminous IR galaxies, recently discovered at high redshifts, in terms of the emission from an active nucleus embedded in a torus-like dusty…

Astrophysics · Physics 2009-10-28 Gian Luigi Granato , Luigi Danese , Alberto Franceschini

We use JWST/MIRI MRS spectroscopy of a sample of six local obscured type 1.9/2 active galactic nuclei (AGN) to compare their nuclear mid-IR absorption bands with the level of nuclear obscuration traced by X-rays. This study is the first to…

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…

We present a compositional analysis of 8-13um spectra of 32 young stellar objects (YSOs). Our sample consists of 5 intermediate-mass stars and 27 low-mass stars. While the spectra and first scientific results have already been published by…

Astrophysics · Physics 2009-11-11 A. Schegerer , S. Wolf , N. V. Voshchinnikov , F. Przygodda , J. E. Kessler-Silacci