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Related papers: The Radiative Efficiency of Hot Accretion Flows

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We have explored the structure of hot flow bathed in a general large-scale magnetic field. The importance of outflow and thermal conduction on the self-similar structure of a hot accretion flows has been investigated. We consider the…

High Energy Astrophysical Phenomena · Physics 2015-06-05 A. Mosallanezhad , M. Khajavi , S. Abbassi

We investigate state transitions in black hole X-ray binaries through different parameters by using two-dimensional axisymmetric hydrodynamical simulation method. For radiative cooling in hot accretion flow, we take into account the…

High Energy Astrophysical Phenomena · Physics 2016-04-20 Mao-Chun Wu , Fu-Guo Xie , Ye-Fei Yuan , Zhao-Ming Gan

We consider an accretion flow model originally proposed by Bisnovatyi-Kogan & Ruzmaikin (1974), which has been confirmed in recent 3D MHD simulations. In the model, the accreting gas drags in a strong poloidal magnetic field to the center…

Astrophysics · Physics 2015-06-24 Ramesh Narayan , Igor V. Igumenshchev , Marek A. Abramowicz

We perform two-dimensional radiation hydrodynamical simulations of accretion flows onto black holes (BHs) at the nuclei of protogalaxies, and study the impact of mechanical and radiative feedback on rapid growth of BHs. The outflows deposit…

High Energy Astrophysical Phenomena · Physics 2020-07-15 Eishun Takeo , Kohei Inayoshi , Shin Mineshige

The temperature of hot accretion flows around black holes is sufficiently high for the ignition of nuclear reactions. This is potentially an important nucleosynthesis mechanism in the universe. As the first step in studying this problem, we…

High Energy Astrophysical Phenomena · Physics 2015-05-13 H. Zhang , Y. Wang , F. Yuan , F. Ding , X. L. Luo , Q. H. Peng

We calculate the evaporation of a cool accretion disk around a black hole due to the ion-bombardment by an ion supported accretion flow (here ISAF, or optically thin ADAF). As first suggested by Spruit & Deufel (2002), this evaporation…

Astrophysics · Physics 2009-11-10 C. P. Dullemond , H. C. Spruit

We review basic properties of advection-dominated accretion flows (ADAFs) and their applications to astrophysical systems ranging from Galactic binary systems to galactic nuclei. A new classification scheme for low-luminosity, X-ray bright…

Astrophysics · Physics 2007-05-23 Insu Yi

It is difficult to implement numerical simulations on a region extending from the vicinity of a black hole to the Bondi radius. Most previous numerical simulations have primarily concentrated on the region close to the black hole. They…

High Energy Astrophysical Phenomena · Physics 2026-05-13 Mu-Qing Liu , Xiao-Hong Yang , De-Fu Bu

We present time-dependent models of the accretion disks created during compact object mergers, focusing on the energy available from accretion at late times and the composition of the disk and its outflows. We calculate the dynamics near…

Astrophysics · Physics 2009-11-13 B. D. Metzger , A. L. Piro , E. Quataert

We investigated effects on flow variables of transonic advection-dominated accretion flows (ADAFs) for different outer boundary locations (BLs) with a changing energy constant ($E$) of the flow. We used the ADAF solutions and investigated a…

High Energy Astrophysical Phenomena · Physics 2019-05-15 Rajiv Kumar , Wei-Min Gu

When gas accretes onto a black hole, at a rate either much less than or much greater than the Eddington rate, it is likely to do so in an "adiabatic" or radiatively inefficient manner. Under fluid (as opposed to MHD) conditions, the disk…

Astrophysics · Physics 2009-11-07 Roger D. Blandford , Mitchell C. Begelman

We consider non-local effects which arise when radiation emitted at one radius of an accretion disk either heats or cools gas at other radii through Compton scattering. We discuss three situations: 1. Radiation from the inner regions of an…

Astrophysics · Physics 2016-08-30 Ann A. Esin

We present self-similar solutions for advection-dominated accretion flows with radial viscous force in the presence of outflows from the accretion flow or infall. The axisymmetric flow is treated in variables integrated over polar sections…

Astrophysics · Physics 2009-10-31 Thomas Beckert

We present time-dependent simulations of a two-phase accretion flow around a black hole. The accretion flow initially is composed of an optically thick and cool disc close to the midplane, while on top and below the disc there is a hot and…

Astrophysics · Physics 2008-11-26 M. Mayer , J. E. Pringle

We implement a new semi-analytical approach to investigate radially self-similar solutions for the steady-state advection-dominated accretion flows (ADAFs). We employ the usual $\alpha$-prescription for the viscosity and all the components…

High Energy Astrophysical Phenomena · Physics 2018-08-08 Asiyeh Habibi , Shahram Abbassi , Mohsen Shadmehri

We investigate the spectral energy distribution (SED) of the supercritical disk accretion flows around black holes by solving the multi-frequency zeroth moment equation of the radiation transfer equation under the flux-limited diffusion…

Astrophysics · Physics 2009-11-10 K. Ohsuga , S. Mineshige , K. Watarai

We investigate the behaviour of dissipative accreting matter close to a black hole as it provides the important observational features of galactic and extra-galactic black holes candidates. We find the complete set of global solutions in…

Astrophysics · Physics 2008-11-26 Santabrata Das

We perform time-dependent, 2DHD numerical simulations to study the dynamics of a slowly rotating accretion flow from sub-pc to pc scales under the irradiation from the central AGN. Compared to previous work, we improve the calculation of…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Chao Liu , Feng Yuan , Jeremiah P. Ostriker , Zhaoming Gan , Xiaohong Yang

The observation of the hot gas surrounding Sgr $A^*$ and a few other nearby galactic nuclei imply that electron and proton mean free paths are comparable to the gas capture radius. So, the hot accretion flows is likely to proceed under…

Astrophysics · Physics 2011-08-31 S. Abbassi , J. Ghanbari , S. Najjar

We reformulate the adiabatic inflow-outflow (ADIOS) model for radiatively inefficient accretion flows, treating the inflow and outflow zones on an equal footing. For purely adiabatic flows (i.e., with no radiative losses), we show that the…

High Energy Astrophysical Phenomena · Physics 2015-05-30 Mitchell C. Begelman
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