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Related papers: Covering factor of the dust-driven broad-line regi…

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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 derive a theoretical relation between $R_{BLR}$, the size of the broad-emission-line region of active galactic nuclei, and the observed soft X-ray luminosity and spectrum. We show that in addition to the well known $R_{BLR}\sim L^{1/2}$…

Astrophysics · Physics 2007-05-23 Amri Wandel

The properties of large-scale galactic outflows, such as their kinetic energy and momentum rates, correlate with the luminosity of the active galactic nucleus (AGN). This is well explained by the wind-driven outflow model, where a fraction…

Astrophysics of Galaxies · Physics 2020-09-30 Kastytis Zubovas , Emanuele Nardini

The winds of ionized gas driven by Active Galactic Nuclei (AGN) can be studied through absorption lines in their X-ray spectra. A recurring feature of these outflows is their broad ionization distribution, including essentially all…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Jonathan Stern , Ehud Behar , Ari Laor , Alexei Baskin , Tomer Holczer

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

The formation of quasar broad-line region (BLR) clouds via thermal instability in the presence of Alfven heating has been discussed by Goncalves et al. (1993a, 1996). In particular, these studies showed the relevance of Alfven heating in…

Astrophysics · Physics 2009-11-07 D. R. Goncalves , A. C. S. Friaca , V. Jatenco-Pereira

Motivated by the discovery of the non-thermal Fermi bubble features both below and above the Galactic plane, we investigate a scenario in which these bubbles are formed through Galacto-centric outflow. Cosmic rays (CR) both diffusing and…

High Energy Astrophysical Phenomena · Physics 2017-01-11 Andrew M. Taylor , Gwenael Giacinti

The feedback from galactic outflows is thought to play an important role in shaping the gas content, star formation history, and ultimately the stellar mass function of galaxies. Here we present evidence for massive molecular outflows…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Aeree Chung , Min S. Yun , Gopal Naraynan , Mark Heyer , Neal R. Erickson

We study the effects of a detailed dust treatment on the properties and evolution of early-type galaxies containing central black holes, as determined by AGN feedback. We find that during cooling flow episodes, radiation pressure on the…

Astrophysics of Galaxies · Physics 2015-06-18 Brandon S. Hensley , Jeremiah P. Ostriker , Luca Ciotti

Observations of ionised carbon at 158 micron ([CII]) from luminous star-forming galaxies at z~0 show that their ratios of [CII] to far infrared (FIR) luminosity are systematically lower than those of more modestly star-forming galaxies. In…

Astrophysics of Galaxies · Physics 2017-02-22 Desika Narayanan , Mark Krumholz

We propose to use degree-scale angular clustering of fast radio bursts (FRBs) to identify their origin and the host galaxy population. We study the information content in autocorrelation of the angular positions and dispersion measures (DM)…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-03 Masato Shirasaki , Kazumi Kashiyama , Naoki Yoshida

The Bloated Stars Scenario proposes that AGN broad line emission originates in the winds or envelopes of bloated stars (BS). Alexander and Netzer (1994) established that ~ 5e4 BSs with dense, decelerating winds can reproduce the observed…

Astrophysics · Physics 2015-06-24 Tal Alexander , Hagai Netzer

Many Active Galactic Nuclei (AGN) are surrounded by gas which absorbs the radiation produced by accretion onto the central black hole and obscures the nucleus from direct view. The dust component of the gas greatly enhances the effect of…

Astrophysics · Physics 2009-11-13 A. C. Fabian , R. V. Vasudevan , P. Gandhi

It is typically assumed that radiation pressure driven winds are accelerated to an asymptotic velocity of V ~ v_esc, where v_esc is the escape velocity from the central source. We note that this is not the case for dusty shells and clouds.…

Astrophysics of Galaxies · Physics 2015-06-22 Todd A. Thompson , Andrew C. Fabian , Eliot Quataert , Norman Murray

Velocity-resolved reverberation mapping suggests that the broad-line regions (BLRs) of AGNs can have significant net inflow. We use the STOKES radiative transfer code to show that electron and Rayleigh scattering off the BLR and torus…

Astrophysics · Physics 2015-03-13 C. Martin Gaskell , Rene W. Goosmann

The Fermi-LAT data revealed giant bubbles of emission above and below the Galactic plane with an energy spectrum significantly harder than seen from other directions. How the bubbles connect to the Galactic plane is unclear. We find that…

High Energy Astrophysical Phenomena · Physics 2015-09-18 Wim de Boer , Iris Gebauer , Simon Kunz , Alexander Neumann

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 work is part of an ongoing effort aiming at identifying the actual wind-drivers among the dust species observed in circumstellar envelopes. In particular, we focus on the interplay between a strong stellar radiation field and the dust…

Solar and Stellar Astrophysics · Physics 2013-02-27 Sara Bladh , Susanne Höfner

${\bf Aim:}$ To test the hypothesis that radiation pressure from star clusters acting on dust is the dominant feedback agent disrupting the largest star-forming molecular clouds and thus regulating the star-formation process. ${\bf…

Astrophysics of Galaxies · Physics 2018-04-11 Stefan Reissl , Ralf S. Klessen , Mordecai-Mark Mac Low , Eric W. Pellegrini

Due to their relation to massive stars, long-duration gamma-ray bursts (GRBs) allow pinpointing star formation in galaxies independently of redshift, dust obscuration, or galaxy mass/size, thus providing a unique tool to investigate the…