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Related papers: COLD ACCRETION DISKS WITH CORONAE AND ADVECTION

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The global nonlinear time dependent evolution of accretion disk-corona systems in X-ray binary sources has been investigated to provide an understanding of the low frequency ($\sim 0.04$~Hz) quasi-periodic oscillations (QPOs) observed…

Astrophysics · Physics 2009-10-28 Marek A. Abramowicz , Xingming Chen , Ronald E. Taam

The vertical structure of optically thick accretion disks is investigated in the two-zone approximation. The disk is divided into an underlying disk and a corona, where the latter is defined as the upper surface layers for which the…

Astrophysics · Physics 2009-11-07 Ranjeev Misra , R. E. Taam

We study an accretion disc with a hot continuous corona. We assume that the corona itself accretes and therefore it is powered directly by the release of the gravitational energy and cooled by radiative interaction with the disc. We…

Astrophysics · Physics 2015-06-24 H. J. Witt , B. Czerny , P. T. Zycki

The time dependent evolution of the accretion disk around black hole is computed. The classical description of the $\alpha$-viscosity is adopted so the evolution is driven by the instability operating in the innermost radiation-pressure…

Astrophysics · Physics 2009-11-07 Agnieszka Janiuk , Bozena Czerny , Aneta Siemiginowska

We present a model for a corona above a geometrically thin standard disk around a black hole. This corona is fed by matter from the thin disk which evaporates from the cool layers underneath. An equilibrium establishes between the cool…

Astrophysics · Physics 2007-05-23 Friedrich Meyer , Bifang Liu , Emmi Meyer-Hofmeister

We study the effects of thermal conduction in a hot, active corona above an accretion disk. We assume that all of the dissipative heating takes place in the corona. We find that the importance of conduction decreases with increases in the…

Astrophysics · Physics 2009-10-30 Andrzej Maciolek-Niedzwiecki , Julian H. Krolik , Andrzej A. Zdziarski

This study investigates the thermal stability of thin accretion disks in high-energy astrophysical systems, incorporating the effects of magnetic fields, winds, and coronae. We analyze how these factors influence disk stability, focusing on…

High Energy Astrophysical Phenomena · Physics 2025-01-28 Arezoo Tajmohamadi , Shahram Abbassi

Non-thermal X-ray emission in compact accretion engines can be interpreted to result from magnetic dissipation in an optically thin magnetized corona above an optically thick accretion disk. If coronal magnetic field originates in the disk…

High Energy Astrophysical Phenomena · Physics 2011-02-11 Eric G. Blackman , Martin E. Pessah

The global structure of optically thin hot accretion disks with radial advection included has been investigated. We solve the full energy conservation equation explicitly and construct the radial structure of the disk. It is found that…

Astrophysics · Physics 2016-08-30 Xingming Chen

We apply the disk-corona evaporation model (Meyer & Meyer-Hofmeister) originally derived for dwarf novae to black hole systems. This model describes the transition of a thin cool outer disk to a hot coronal flow. The mass accretion rate…

Astrophysics · Physics 2009-10-31 B. F. Liu , W. Yuan , F. Meyer , E. Meyer-Hofmeister , G. Z. Xie

We study the steady-state structure of an accretion disc with a corona surrounding a central, rotating, magnetized star. We assume that the magneto-rotational instability is the dominant mechanism of angular momentum transport inside the…

Astrophysics · Physics 2009-06-23 Fazeleh Khajenabi , Mohsen Shadmehri , Sami Dib

Thermal conduction between a cool accretion disk and a hot inner corona can result in either evaporation of the disk or condensation of the hot corona. At low mass accretion rates, evaporation dominates and can completely remove the inner…

High Energy Astrophysical Phenomena · Physics 2015-05-20 B. F. Liu , C. Done , Ronald E. Taam

We consider the role of advection in the two-temperature accreting corona with an underlying optically thick disc. The properties of coronal solutions depend significantly on the description of advection. Local parameterization of advection…

Astrophysics · Physics 2009-10-31 Agnieszka Janiuk , Piotr T. Zycki , Bozena Czerny

In the past years, several observations of AGN and X-ray binaries have suggested the existence of a warm T around 0.5-1 keV and optically thick, \tau ~ 10-20, corona covering the inner parts of the accretion disk. These properties are…

Astrophysics of Galaxies · Physics 2015-08-05 A. Rozanska , J. Malzac , R. Belmont , B. Czerny , P. -O. Petrucci

We develop a two-flow model of accretion onto a black hole which incorporates the effect of the local magneto-rotational instability. The flow consists of an accretion disk and an accreting corona, and the local dynamo affects the…

Astrophysics · Physics 2009-11-13 A. Janiuk , B. Czerny

The formation of a cool disk in the innermost regions of black hole X-ray transient systems in the low hard state is investigated. Taking into account the combined cooling associated with the Compton and conductive energy transport…

Astrophysics · Physics 2009-11-13 Ronald E. Taam , B. F. Liu , F. Meyer , E. Meyer-Hofmeister

The spectral energy distributions of galactic black holes in the low/hard state and of low-luminosity AGN possess many common features, the most prominent being: compact, flat (or inverted) spectrum radio cores with high brightness…

Astrophysics · Physics 2009-09-17 A. Merloni , A. C. Fabian

We discuss a model for the central region of radio-quiet AGN in which coronal accretion is the source of energy for X-ray emission. We start from the Haardt & Maraschi model but supplement it with pressure balance condition, two…

Astrophysics · Physics 2015-06-24 P. T. Zycki , S. Collin-Souffrin , B. Czerny

The steady-state structure of a disc with a corona is analyzed when the vertical component of the gravitational force due to the self-gravity of the disc is considered. For the energy exchange between the disc and the corona, we assume a…

Astrophysics · Physics 2009-11-13 Fazeleh Khajenabi , Peter Duffy

X-ray observations of the tidal disruption event (TDE) candidate AT 2019avd show drastic variabilities in flux and spectral shape over hundreds of days, providing clues on the accretion disc-corona evolution. We utilize a disc-corona model,…

High Energy Astrophysical Phenomena · Physics 2026-03-27 Haichao Xu , Xinwu Cao , Yanan Wang , Andrzej A. Zdziarski
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