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Related papers: Radiatively inefficient accretion disks

200 papers

We derive all relevant equations needed for constructing a global general relativistic model of advectively cooled, very hot, optically thin accretion disks around black holes and present solutions which describe advection dominated flows…

Astrophysics · Physics 2009-10-28 M. A. Abramowicz , X. -M. Chen , M. Granath , J. -P. Lasota

We consider the effects of advection and radial gradients of pressure and radial drift velocity on the structure of optically thick accretion disks. We concentrate our efforts on highly viscous disks, $\alpha=1.0$, with large accretion…

Astrophysics · Physics 2007-05-23 I. V. Artemova , G. S. Bisnovatyi-Kogan , G. Bjoernsson , I. D. Novikov

This is an introduction to models of accretion discs around black holes. After a presentation of the non-relativistic equations describing the structure and evolution of geometrically thin accretion discs we discuss their steady-state…

High Energy Astrophysical Phenomena · Physics 2016-08-17 Jean-Pierre Lasota

Outflows and convective motions in accretion flows have been intensively discussed recently in the context of advection-dominated accretion flow (ADAF) based on two-dimensional (2D) and three-dimensional (3D) hydrodynamical simulations. We,…

Astrophysics · Physics 2007-05-23 Mami Machida , Ryoji Matsumoto , and Shin Mineshige

We consider time-dependent models for rotating accretion flows onto black holes, where a transition takes place from an outer cooling-dominated disc to a radiatively inefficient flow in the inner region. In order to allow for a transition…

Astrophysics · Physics 2009-11-07 J. Gracia , J. Peitz , Ch. Keller , M. Camenzind

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

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

The existence of outflow and magnetic field in the inner region of hot accretion flows have been confirmed by observations and numerical magnetohydrodynamic simulations (MHD). We present self-similar solutions for radiation inefficiently…

Astrophysics of Galaxies · Physics 2015-06-05 S. Abbassi , A. Mosallanezhad

Radiatively inefficient accretion flows (RIAFs) are common feature of low-luminosity accretion flows, including quiescent states of X-ray binaries and low-lunimosity active galactic nuclei. Thermally driven winds are expected from such hot…

High Energy Astrophysical Phenomena · Physics 2015-05-13 Ryoji Kawabata , Shin Mineshige

It is commonly believed that accretion discs are truncated and their inner regions are described by advection dominated accretion flows (ADAFs) in the hard spectral state of black hole X-ray binaries. However, the increasing occurrence of a…

High Energy Astrophysical Phenomena · Physics 2023-11-09 Yilong Wang , Bifang Liu , Erlin Qiao , Huaqing Cheng

We solved analytically viscous two-dimensional (2D) fluid equations for accretion and outflows in spherical polar coordinates ($r, \theta, \phi$) and obtained explicitly flow variables in $r-$ and $\theta -$directions around black holes…

High Energy Astrophysical Phenomena · Physics 2018-07-04 Rajiv Kumar , Wei-Min Gu

We propose a model of the accretion flow onto a black hole consisting of the accretion disk with an accreting two-temperature corona. The model is based on assumptions about the radiative and conductive energy exchange between the two…

Astrophysics · Physics 2009-10-31 B. Czerny , A. Rozanska , A. Janiuk , P. T. Zycki

The concept of an advection-dominated accretion flow (ADAF), with or without wind loss, was used to describe the spectra of the galactic center source Sgr A*, low-luminosity AGN and nuclei of elliptical galaxies (including M87). The…

Astrophysics · Physics 2009-11-06 Bifang Liu , Emmi Meyer-Hofmeister

Context: Accretion onto galactic and supermassive black holes occurs in different modes, which are documented in hard and soft spectral states, commonly attributed to an advection-dominated flow (ADAF) inside a truncated disk and standard…

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

We review the current understanding of accretion flows around compact objects with a special emphasis on advective disks. We discuss the influence of the centrifugal pressure supported high density region around compact objects (where…

Astrophysics · Physics 2007-05-23 Sandip K. Chakrabarti

We study the global dynamics of advection-dominated accretion flows (ADAFs) with magnetically driven outflows. A fraction of gases in the accretion flow is accelerated into the outflows, which leads to decreasing of the mass accretion rate…

High Energy Astrophysical Phenomena · Physics 2015-05-14 Shuang-Liang Li , Xinwu Cao

These notes introduce and review some of the physical principles underlying the theory of astrophysical accretion, emphasizing the central roles of angular momentum transport, angular momentum loss, and radiative cooling in determining the…

High Energy Astrophysical Phenomena · Physics 2022-01-20 Philip J. Armitage

As the luminosity of an accreting black hole drops to a few percent of Eddington, the spectrum switches from the familiar soft state to a hard state that is well-described by a distended and tenuous advection-dominated accretion flow…

Astrophysics · Physics 2009-06-23 Ramesh Narayan , Jeffrey E. McClintock

Advection-dominated, high-temperature, quasi-spherical accretion flow onto a compact object, recently considered by a number of authors, assume that the dissipation of turbulent energy of the flow heats the ions and that the dissipated…

Astrophysics · Physics 2009-10-30 G. S. Bisnovatyi-Kogan , R. V. E. Lovelace

Jets and outflows are known to form out of advective accretion flows around black holes. Hard photons from the centrifugal barrier directly hit the electrons and deposit momentum on them. For optically thick flows such deposition is not…

Astrophysics · Physics 2009-10-31 Indranil Chattopadhyay , Sandip K. Chakrabarti