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We investigate the accretion process in high-luminosity AGNs (HLAGNs) in the scenario of the disk evaporation model. Based on this model, the thin disk can extend down to the innermost stable circular orbit (ISCO) at accretion rates higher…

High Energy Astrophysical Phenomena · Physics 2015-06-05 J. Y. Liu , B. F. Liu , E. L. Qiao , S. Mineshige

In this paper we consider two outstanding intertwined problems in modern high-energy astrophysics: (1) the vertical thermal structure of an optically thick accretion disk heated by the dissipation of magnetohydrodynamic (MHD) turbulence…

High Energy Astrophysical Phenomena · Physics 2015-06-05 Dmitri A. Uzdensky

A long-standing question in active galactic nucleus (AGN) research is how the corona is heated up to produce X-ray radiation much stronger than that arising from the viscous heating within the corona. In this paper, we carry out detailed…

High Energy Astrophysical Phenomena · Physics 2020-06-05 Huaqing Cheng , B. F. Liu , Jieying Liu , Zhu Liu , Erlin Qiao , Weimin Yuan

It is commonly believed that the optical/UV and X-ray emissions in luminous AGN are produced in an accretion disk and an embedded hot corona respectively. The inverse Compton scattering of disk photons by hot electrons in the corona can…

High Energy Astrophysical Phenomena · Physics 2015-05-05 B. F. Liu , R. E. Taam , E. Qiao , W. Yuan

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

Popular models for the formation of X-ray spectra in AGN assume that a large fraction of the disk's angular momentum dissipation takes place in a hot corona that carries a small amount of the accreting mass. Here I discuss the formation of…

Astrophysics · Physics 2007-05-23 Tiziana Di Matteo

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

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

We study the possibility of a cool disk existing in the Galactic Center in the framework of the disk-corona evaporation/condensation model. Assuming an inactive disk, a hot corona should form above the disk since there is a continuous…

Astrophysics · Physics 2009-11-10 B. F. Liu , F. Meyer , E. Meyer-Hofmeister

We obtained thermal equilibrium solutions for optically thin, two-temperature black hole accretion disks incorporating magnetic fields. The main objective of this study is to explain the bright/hard state observed during the bright/slow…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Hiroshi Oda , Mami Machida , Kenji E. Nakamura , Ryoji Matsumoto

Cold optically thick accretion disks with hot coronae and radial advection have been investigated. Within the framework of $\alpha$-viscosity models, we assume that all the mass accretion and angular momentum transport take place in the…

Astrophysics · Physics 2009-10-28 Xingming Chen

State transitions in black hole X-ray binaries are likely caused by gas evaporation from a thin accretion disk into a hot corona. We present a height-integrated version of this process which is suitable for analytical and numerical studies.…

High Energy Astrophysical Phenomena · Physics 2022-06-24 Hyerin Cho , Ramesh Narayan

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

Stellar mass black holes in X-ray binaries (XRBs) are known to display different states characterized by different spectral and timing properties, understood in the framework of a hot corona coexisting with a thin accretion disk whose inner…

High Energy Astrophysical Phenomena · Physics 2024-04-29 Rodrigo Nemmen , Artur Vemado , Ivan Almeida , Javier Garcia , Pedro Motta

We present the properties of accretion disk corona (ADC) models, where the radiation field, the temperature, and the total opacity of the corona are determined self-consistently. We use a non-linear Monte Carlo code to perform the…

Astrophysics · Physics 2009-10-30 James B. Dove , Jorn Wilms , Mitchell C. Begelman

We present the results of self-consistent models of Compton-heated accretion disk coronae. The models are calculated using a new method for computing monochromatic radiative transfer in two-dimensions. The method splits the radiation into…

Astrophysics · Physics 2009-10-22 Stephen D. Murray , John I. Castor , Richard I. Klein , Christopher F. McKee

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

The heating mechanism of a corona above an accretion disk in active galactic nuclei (AGNs) is still unknown. One possible mechanism is magnetic reconnection heating requiring energy equipartition between magnetic energy and gas energy in…

High Energy Astrophysical Phenomena · Physics 2014-11-11 Yoshiyuki Inoue , Akihiro Doi

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

We build a self-consistent model of a warm scattering corona near an accreting black hole in Kerr geometry, in the regime of slow ($\sim 0.01$ Eddington) mass accretion. An iterative Monte Carlo procedure is developed that incorporates…

High Energy Astrophysical Phenomena · Physics 2026-04-29 Jonathan Zhang , Christopher Thompson