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Related papers: Thermal radiation from an accretion disk

200 papers

In the initial formation stages young stars must acquire a significant fraction of their mass by accretion from a circumstellar disk that forms in the center of a collapsing protostellar cloud. Throughout this period mass accretion rates…

Astrophysics · Physics 2009-11-13 Roman Rafikov

The standard thin accretion disk model has been successfully used to explain the soft X-ray spectra of Galactic black hole systems and perhaps the UV emission of Active Galactic Nuclei. However, radiation pressure dominated disks are known…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Agnieszka Janiuk , Ranjeev Misra

The tidal disruption of a star by a supermassive black hole is expected to lead to a short bright flare followed by an extended period of low-level emission. Existing models of the late-time accretion of the stellar debris via a thin disk…

Astrophysics · Physics 2009-11-07 Kristen Menou , Eliot Quataert

We perform 2D and 3D kinetic simulations of reconnection-mediated turbulent flares in a magnetized electron-positron plasma, with weak and strong radiative cooling. Such flares can be generated around neutron stars and accreting black…

High Energy Astrophysical Phenomena · Physics 2021-11-17 J. Nättilä , A. M. Beloborodov

Black holes may accrete gas with angular momentum vectors misaligned with the black hole spin axis. The resulting accretion disks are subject to Lense-Thirring precession, and hence torque. Analytical calculations and simulations show that…

High Energy Astrophysical Phenomena · Physics 2025-01-27 J. Speicher , O. Blaes

A theory of thermal and nonthermal radiation in a vacuum background of arbitrary temperature generated by relativistic polarizable particle with spin is proposed. When the particle rotates, radiation is produced by vacuum fluctuations even…

Mesoscale and Nanoscale Physics · Physics 2014-12-17 A. A. Kyasov , G. V Dedkov

We investigate the thermal stability of the outer layers of accretion discs in which the local viscous energy dissipation rate scales with the pressure as for standard Shakura-Sunyaev discs. By solving for the accretion disc vertical…

Astrophysics · Physics 2009-10-31 Martijn de Kool , Dayal T. Wickramasinghe

We calculated the bolometric images of relativistic slim disks during radiation-pressure-driven thermal instability. When the mass-accretion rate exceeds the critical one, an inner region of the standard accretion disk bursts to change to a…

Astrophysics · Physics 2007-05-23 Akihiro Kawata , Ken-ya Watarai , Jun Fukue

We study the nucleosynthesis in accretion disk around compact object. When matter falls towards the compact object, due to interactions in nuclear species nuclear energy is released in the high temperature. In some region of parameter space…

Astrophysics · Physics 2017-08-23 Banibrata Mukhopadhyay

Sgr~A* often shows bright, episodic flares observationally, the mechanism of the flares intermittent brightening is not very clear. Many people believe the flares may formed by the non-thermal particles, which can be a consequence of the…

High Energy Astrophysical Phenomena · Physics 2024-07-03 TianLe-Zhao , XiaoFeng-Li , ZeYuan-Tang , Rajiv Kumar

Thermal radiation from hot polar caps is examined in radio pulsars with drifting subpulses. It is argued that if these subpulses correspond to sparking discharges of the inner acceleration region right above the polar cap surface then a…

Astrophysics · Physics 2007-05-23 Janusz Gil , George Melikidze , Bing Zhang

Laser experiments with optically excited frozen gases entail the excitation of polarization waves. In a continuum approximation the waves are dispersionless, but their frequency depends on the direction of the propagation vector. An outline…

Disordered Systems and Neural Networks · Physics 2007-05-23 V. Celli , J. S. Frasier

The conventional thermal instability criterion can not be applied to the advection-dominated accretion disks around black holes where the radiative cooling is insufficient to balance the viscous heating. The surface density change…

Astrophysics · Physics 2015-06-24 Xue-Bing Wu

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

We here examine the conditions of the two-phase disk model under which magnetic flares arise above the cold accretion disk due to magnetic buoyancy and produce X-rays via Comptonization of the disk's soft radiation. We find that the disk's…

Astrophysics · Physics 2007-05-23 Sergei Nayakshin , Fulvio Melia

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 study gravitational-wave emission by turbulent flows in accretion disks around spinning black holes or neutron stars. We aim to understand how turbulence can stochastically excite black hole quasinormal ringing and contribute to a…

General Relativity and Quantum Cosmology · Physics 2025-02-13 Chen Yuan , Vitor Cardoso , Francisco Duque , Ziri Younsi

We examine radiation and its effects on accretion disks orbiting astrophysical black holes. These disks are thermally radiating and can be geometrically and optically thin or thick. In this first paper of the series, we discuss the physics…

Instrumentation and Methods for Astrophysics · Physics 2022-12-06 Leela Elpida Koutsantoniou

Geometrically thick disks may form after tidal disruption events, and rapid accretion may lead to short flares followed by long-term, lower-level emission. Using a novel accretion disk code which relies primarily on global conservation laws…

Astrophysics · Physics 2007-05-23 Andrew Ulmer

We have developed a three-dimensional numerical model and applied it to simulate plasma flows in semi-detached binary systems whose accretor possesses a strong intrinsic magnetic field. The model is based on the assumption that the plasma…

Solar and Stellar Astrophysics · Physics 2010-10-26 A. G. Zhilkin , D. V. Bisikalo