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Related papers: Accretion Disks in AGNs

200 papers

We present the results of local, vertically stratified, radiation magnetohydrodynamic shearing box simulations of magnetorotational instability (MRI) turbulence for a (hydrogen poor) composition applicable to accretion disks in AM CVn type…

Solar and Stellar Astrophysics · Physics 2018-04-25 Matthew S. B. Coleman , Omer Blaes , Shigenobu Hirose , Peter H. Hauschildt

Accretion disks in Active Galactic Nuclei (AGN) are predicted to become gravitationally unstable substantially interior to the black hole's sphere of influence, at radii where the disk is simultaneously unstable to the magnetorotational…

High Energy Astrophysical Phenomena · Physics 2025-07-30 Tsun Hin Navin Tsung , Mitchell C. Begelman , Philip J. Armitage , Yan-Fei Jiang , Hannalore J. Gerling-Dunsmore

Accretion onto a compact object must occur through a disc when the material has some initial angular momentum. Thin discs and the thicker low radiative efficiency accretion flows are solutions to this problem that have been widely studied…

Astrophysics · Physics 2015-06-24 Guillaume Dubus

Accretion onto supermassive black holes produces both the dramatic phenomena associated with active galactic nuclei and the underwhelming displays seen in the Galactic Center and most other nearby galaxies. I review selected aspects of the…

Astrophysics · Physics 2016-01-27 Philip J. Armitage

Variability studies hold information on otherwise unresolvable regions in Active Galactic Nuclei (AGN). Population studies of large samples likewise have been very productive for our understanding of AGN. These two themes are coming…

High Energy Astrophysical Phenomena · Physics 2016-05-31 Andy Lawrence

A brief overview is given of the observations of accretion disks in X-ray binaries, discussing their geometry, their effect on the rotation period of the accreting object, their optical and X-ray spectra, time variability, and radio…

Astrophysics · Physics 2007-05-23 Frank Verbunt

Truncated accretion disks are commonly invoked to explain the spectro-temporal variability from accreting black holes in both small systems, i.e. state transitions in galactic black hole binaries (GBHBs), and large systems, i.e.…

High Energy Astrophysical Phenomena · Physics 2017-07-19 J. Drew Hogg , Christopher S. Reynolds

Disk continuum reverberation mapping is one of the primary ways we learn about active galactic nuclei (AGN) accretion disks. Reverberation mapping assumes that time-varying X-rays incident on the accretion disk drive variability in…

High Energy Astrophysical Phenomena · Physics 2025-01-14 Amy Secunda , Yan-Fei Jiang , Jenny E. Greene

We present a non-linear numerical model for a geometrically thin accretion disk with the addition of stochastic non-linear fluctuations in the viscous parameter. These numerical realizations attempt to study the stochastic effects on the…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Philip S. Cowperthwaite , Christopher S. Reynolds

These lectures provide an overview of the theory of accretion disks with application to bright sources containing black holes. I focus on the fundamental physics of these flows, stressing modern developments and outstanding questions…

Astrophysics · Physics 2007-05-23 O. M. Blaes

We calculate the radiation spectrum and its time variability of the black hole accretion disk-corona system based on the three-dimensional magnetohydrodynamic simulation. In explaining the spectral properties of active galactic nuclei…

Astrophysics · Physics 2015-05-13 Norita Kawanaka , Yoshiaki Kato , Shin Mineshige

In the innermost regions of Active Galactic Nuclei (AGN), matter is understood to be flowing onto the Supermassive black hole (SMBH), which forms an accretion disk. This disk is responsible for the optical/UV continuum emission observed in…

High Energy Astrophysical Phenomena · Physics 2023-08-01 Vivek Kumar Jha , Ravi Joshi , Jayesh Saraswat , Hum Chand , Sudhanshu Barway , Amit Kumar Mandal

We review recent progress on the modeling and use of reflection spectra from irradiated and ionized accretion discs. On the computational side, calculations of reflection spectra from discs with non-uniform density structure have shown that…

Astrophysics · Physics 2007-05-23 D. R. Ballantyne , R. R. Ross , A. C. Fabian

As the title suggests, the purpose of this chapter is to review the current status of numerical simulations of black hole accretion disks. This chapter focuses exclusively on global simulations of the accretion process within a few tens of…

High Energy Astrophysical Phenomena · Physics 2015-06-15 P. Chris Fragile

The existing disk instability model for dwarf nova eruptions is reviewed, in the light of recent progress in the understanding of angular momentum transport in accretion disks. It is proposed that the standard lower branch in the…

Astrophysics · Physics 2007-05-23 Mario Livio

The standard accretion discs are known to be thermally and viscously unstable over a certain range of temperatures. In the inner disc regions there may develop radiation pressure driven instability, which is possibly related to the rapid…

Astrophysics · Physics 2007-05-23 Agnieszka Janiuk , Bozena Czerny

In this review I concentrate exclusively on models for the large-scale structure created by jet flows in AGN. I briefly mention models for the evolution and emission of these objects and how they can also be applied to microquasars. While…

Astrophysics · Physics 2009-04-14 Christian R. Kaiser

Simulations and analytic arguments suggest that the turbulence driven by magnetorotational instability (MRI) in accretion discs can amplify the toroidal (azimuthal) component of the magnetic field to a point at which magnetic pressure…

Astrophysics · Physics 2008-11-26 M. C. Begelman , J. E. Pringle

One of the most important problems in the study of active galaxies is understanding the detailed geometry, physics, and evolution of the central engines and their environments. The leading models involve an accretion disk and torus…

Astrophysics · Physics 2009-11-10 R. Morganti , L. J. Greenhill , A. B. Peck , D. L. Jones , C. Henkel

We describe the physical mechanisms of launching and acceleration of wind from an active galactic nucleus (AGN) accretion disk. We focus on the radiation line force driven and magnetic driven wind models, which operate on the accretion disk…

High Energy Astrophysical Phenomena · Physics 2024-09-04 De-Fu Bu , Feng Yuan