English
Related papers

Related papers: HOT ACCRETION DISKS WITH ADVECTION

200 papers

We examine a new family of global analytic solutions for optically thick accretion disks, which includes the supercritical accretion regime. We found that the ratio of the advection cooling rate, $Q_{\rm adv}$, to the viscous heating rate,…

Astrophysics · Physics 2016-08-30 K. Watarai

We discuss the properties of an accretion disk around a star with parameters typical of classical T Tauri stars (CTTS), and with the average accretion rate for these disks. The disk is assumed steady and geometrically thin. The turbulent…

Astrophysics · Physics 2011-02-11 Paola D'Alessio , Jorge Canto , Nuria Calvet , Susana Lizano

We describe new optically thin solutions for rotating accretion flows around black holes and neutron stars. These solutions are advection dominated, so that most of the viscously dissipated energy is advected radially with the flow. We…

Astrophysics · Physics 2009-10-22 Ramesh Narayan , Insu Yi

The purpose of this paper is to explore the dynamical behaviour of hot accretion flow with thermal conduction. The importance of thermal conduction on hot accretion flow is confirmed by observations of the hot gas that surrounds Sgr A$^*$…

High Energy Astrophysical Phenomena · Physics 2012-05-11 Kazem Faghei

We study the accretion flow of a hot gas captured by the black hole gravity in the presence of a thin cold accretion disk. Such geometrical arrangement is expected in Active Galactic Nuclei (AGN) and in galactic X-ray binary systems because…

Astrophysics · Physics 2007-05-23 Sergei Nayakshin

Outflows are inevitably driven from the disk if the vertical component of the black hole (BH) gravity cannot resist the radiation force. We derive the mass loss rate in the outflows by solving a dynamical equation for the vertical gas…

High Energy Astrophysical Phenomena · Physics 2022-09-21 Xinwu Cao , Wei-Min Gu

We present an approach to deriving global properties of accretion disks from the knowledge of local solutions derived from numerical simulations based on the shearing box approximation. The approach consists of a two-step procedure. First a…

Solar and Stellar Astrophysics · Physics 2016-03-02 G. Bodo , F. Cattaneo , A. Mignone , F. Ponzo , P. Rossi

Observations and numerical simulations have shown that outflows generally exist in the accretion process. We revisit the thermal equilibrium solutions of black hole accretion flows by including the role of outflows. Our study focuses on the…

High Energy Astrophysical Phenomena · Physics 2022-05-18 Wen-Biao Wu , Wei-Min Gu , Mouyuan Sun

Standard models of radiation supported accretion disks generally assume that diffusive radiation flux is solely responsible for vertical heat transport. This requires that heat must be generated at a critical rate per unit volume if the…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Omer Blaes , Julian H. Krolik , Shigenobu Hirose , Natalia Shabaltas

Total and internal energy requirements set constraints on the allowable temperature on the disk. In a gas pressure dominated disk, they lead to a cooling rate that decreases with temperature. These findings are used to show that the flow is…

Astrophysics · Physics 2007-05-23 Cesar Meirelles Filho , Celso Luiz Lima , Hideaki Miyake

In the dynamics of accretion disks, the presence of collective effects associated with the self-gravity of the disk is expected to affect not only the momentum transport, but also the relevant energy balance equations, which could differ…

Astrophysics · Physics 2009-11-06 G. Bertin , G. Lodato

In the innermost region of the advective accretion disk orbiting a black hole of high spin, the inertia of heat stored in the accreting gas is comparable to that of the gas rest mass itself. Accounting for this effect, we derive additional…

Astrophysics · Physics 2009-10-30 A. M. Beloborodov , M. A. Abramowicz , I. D. Novikov

In standard accretion discs, outward angular momentum transfer by viscous forces is compensated by the inward motion of the accreting matter. However, the vertical structure of real accretion discs leads to meridional circulation with…

High Energy Astrophysical Phenomena · Physics 2017-12-27 Pavel Abolmasov

Using three-dimensional general relativistic magnetohydrodynamic simulations with electron and proton thermodynamics and an electron cooling function, we probe the inner radial and vertical structure of weakly magnetized geometrically thin…

High Energy Astrophysical Phenomena · Physics 2025-08-28 A. Hankla , J. Dexter , N. Scepi

The relations among the relative changes of surface density, temperature, disk height and vertical integrated pressure in three kinds of thermally unstable accretion disks were quantitatively investigated by assuming local perturbations.…

Astrophysics · Physics 2009-10-30 Xue-Bing Wu

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

We use FIRE simulations to study disk formation in z~0, Milky Way-mass galaxies, and conclude that a key ingredient for the formation of thin stellar disks is the ability for accreting gas to develop an aligned angular momentum distribution…

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 paper investigates the influence of accretion heating and turbulent heat conduction on the equilibrium of protoplanetary disks, extending the 2D axis-symmetric passive disk model of Flock (Flock et al. 2016, ApJ 827, 144). The model…

Earth and Planetary Astrophysics · Physics 2021-10-25 B. N. Schobert , A. G. Peeters , F. Rath

Accretion disks are observed in young stars, cataclysmic variables, binary X-ray sources et al. Accretion disk theory was first developed as a theory with the local heat balance, where the whole energy produced by a viscous heating was…

Astrophysics · Physics 2007-05-23 G. S. Bisnovatyi-Kogan