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相关论文: The dust-gas AGN torus as constrained from X-ray a…

200 篇论文

Context: We investigate mid-infrared and X-ray properties of the dusty torus invoked in the unification scenario for active galactic nuclei. Aims: We use the relation between mid IR and hard X-ray luminosities to constrain the geometry and…

天体物理学 · 物理学 2009-11-13 Hannes Horst , Poshak Gandhi , Alain Smette , Wolfgang J. Duschl

We analyze the link between active galactic nuclei (AGN) and mid-infrared flux using dust radiative transfer calculations of starbursts realized in hydrodynamical simulations. Focusing on the effects of galaxy dust, we evaluate diagnostics…

宇宙学与河外天体物理 · 物理学 2013-07-12 Gregory F. Snyder , Christopher C. Hayward , Anna Sajina , Patrik Jonsson , Thomas J. Cox , Lars Hernquist , Philip F. Hopkins , Lin Yan

Approximately 3-17 percent of Active Galactic Nuclei (AGN) without detected rest-frame UV/optical broad emission lines (type-2 AGN) do not show absorption in X-rays. The physical origin behind the apparently discordant optical/X-ray…

Two families of models of dusty tori in AGNs (moderately thick and extended versus very thick and compact) are tested against available observations. The confrontation suggests that the former class better explains the IR broad-band spectra…

天体物理学 · 物理学 2009-10-30 Gian Luigi Granato , Luigi Danese , Alberto Franceschini

In a companion paper, Maiolino et al. (2000) presented various observational evidences for "anomalous" dust properties in the circumnuclear region of AGNs and, in particular, the reduced E(B-V)/N_H and Av/N_H ratios, the absence of the…

天体物理学 · 物理学 2009-10-31 R. Maiolino , A. Marconi , E. Oliva

The spectral energy distributions and infrared (IR) spectra of a sample of obscured AGNs selected in the mid-IR are modeled with recent clumpy torus models to investigate the nature of the sources, the properties of the obscuring matter,…

天体物理学 · 物理学 2010-03-19 M. Polletta , D. Weedman , S. Hoenig , C. J. Lonsdale , H. E. Smith , J. Houck

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…

宇宙学与河外天体物理 · 物理学 2015-05-30 Makoto Kishimoto , Sebastian F. Hoenig , Robert Antonucci , Florentin Millour , Konrad R. W. Tristram , Gerd Weigelt

The unified model of active galactic nuclei (AGN) claims that the properties of AGN depend on the viewing angle of the observer with respect to a toroidal distribution of dust surrounding the nucleus. Both the mid-infrared (MIR) attenuation…

The size and structure of the dusty circumnuclear torus in active galactic nuclei (AGN) can be investigated by analyzing the temporal response of the torus's infrared (IR) dust emission to variations in the AGN ultraviolet/optical…

星系天体物理 · 物理学 2020-03-02 Triana Almeyda , Andrew Robinson , Michael Richmond , Robert Nikutta , Bryanne McDonough

A parsec-scale dusty torus is thought to be the cause of Active Galactic Nuclei (AGN) dichotomy in the 1/2 types, narrow/broad emission lines. In a previous work, on the basis of parsec-scale resolution infrared / optical dust maps it was…

星系天体物理 · 物理学 2021-09-08 Almudena Prieto , Jakub Nadolny , Juan A. Fernández-Ontiveros , Mar Mezcua

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…

Aims: We aim to find torus models that explain the observed high-resolution mid-infrared (MIR) measurements of active galactic nuclei (AGN). Our goal is to determine the general properties of the circumnuclear dusty environments. Methods:…

星系天体物理 · 物理学 2016-06-29 N. López-Gonzaga , W. Jaffe

Recent models for the inner structure of active galactic nuclei (AGN) aim at connecting the outer region of the accretion disk with the broad-line region and dusty torus through a radiatively accelerated, dusty outflow. Such an outflow not…

星系天体物理 · 物理学 2023-09-29 Hermine Landt

Context: We investigate mid-infrared and X-ray properties of the dusty torus in unification scenarios for active galactic nuclei. Aims: We use the relation between mid IR and hard X-ray luminosities to constrain AGN unification scenarios.…

天体物理学 · 物理学 2009-11-11 Hannes Horst , Alain Smette , Poshak Gandhi , Wolfgang J. Duschl

The active galactic nucleus (AGN) phenomena results from a supermassive black hole accreting its surrounding gaseous and dusty material. The infrared (IR) regime provides most of the information to characterize the dusty structures that…

星系天体物理 · 物理学 2022-05-31 Jianwei Lyu , George Rieke

The key ingredient of active galactic nuclei (AGN) unification, the dusty obscuring torus was so far held responsible for the observed mid-infrared (MIR) emission of AGN. However, the best studied objects with VLTI/MIDI show that instead a…

星系天体物理 · 物理学 2019-09-04 Daniel Asmus

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

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…

In this paper, I have attempted to highlight key results from deep extragalactic surveys at mid-infrared wavelengths. I discuss advances in our understanding of dust enshrouded star-formation and AGN activity at 0<z<3 from IRAS, ISO and…

天体物理学 · 物理学 2007-05-23 Ranga-Ram Chary

We derive the properties of dusty tori in Active Galactic Nuclei (AGN) from the comparison of observed Spectral Energy Distributions (SEDs) of SDSS quasars and a precomputed grid of torus models. The observed SEDs comprise SDSS photometry,…