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Related papers: Hot One-Temperature Accretion Flows Revisited

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We quantify the effects of electron thermal conduction on the properties of hot accretion flows, under the assumption of spherical symmetry. Electron heat conduction is important for low accretion rate systems where the electron cooling…

Astrophysics · Physics 2011-02-11 Bryan M. Johnson , Eliot Quataert

Cooling flows in galaxy clusters and isolated elliptical galaxies are a source of mass for fueling accretion onto a central supermassive black hole. We calculate the dynamics of accreting matter in the combined gravitational potential of a…

Astrophysics · Physics 2009-10-31 Eliot Quataert , Ramesh Narayan

We study the thermal structure of the widely adopted two-dimensional advection dominated accretion flow (ADAF) of Narayan & Yi (1995a). The critical radius for a given mass accretion rate, outside of which the optically thin hot solutions…

Astrophysics · Physics 2009-10-31 Myeong-Gu Park , Jeremiah P. Ostriker

Based on a unified description of various accretion flows, we find a long-ignored solution - the effectively optically thin accretion flow, occurring at accretion rates around Eddington value. As a consequence of radiation-pressure…

High Energy Astrophysical Phenomena · Physics 2025-07-01 Mingjun Liu , B. F. Liu , Yilong Wang , Huaqing Cheng , Weimin Yuan

Simple assumptions made regarding electron thermodynamics often limit the extent to which general relativistic magnetohydrodynamic (GRMHD) simulations can be applied to observations of low-luminosity accreting black holes. We present,…

High Energy Astrophysical Phenomena · Physics 2015-10-15 Sean M. Ressler , Alexander Tchekhovskoy , Eliot Quataert , Mani Chandra , Charles F. Gammie

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

Plasmas in an accretion flow are heated by MHD turbulence generated through the magneto-rotational instability. The viscous stress driving the accretion is intimately connected to the microscopic processes of turbulence dissipation. We show…

Astrophysics · Physics 2007-07-04 Siming Liu , Christopher L. Fryer , Hui Li

We report here on a calculation of thermalization time-scale of the two temperature advection dominated accretion flow (ADAF) model. It is established that time required to equalize the electron and ion temperatures via electron-ion…

Astrophysics · Physics 2009-10-31 David Tsiklauri

We investigate the transition of a radiatively inefficient phase of a viscous two temperature accreting flow to a cooling dominated phase and vice versa around black holes. Based on a global sub-Keplerian accretion disc model in steady…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Monika Sinha , S. R. Rajesh , Banibrata Mukhopadhyay

The hot accretion flow is usually optically thin in the radial direction, therefore the photons produced at one radius can travel for a long distance without being absorbed. These photons thus can heat or cool electrons at other radii via…

Astrophysics · Physics 2009-06-23 Feng Yuan , Fuguo Xie , Jeremiah P. Ostriker

In a previous paper, we presented the global solution of a new accretion flow model, namely luminous hot accretion flows (LHAFs). In this {\em Letter}, we first show the corresponding thermal equilibrium curve of LHAFs in the mass accretion…

Astrophysics · Physics 2009-11-07 Feng Yuan

We find a new two-temperature hot branch of equilibrium solutions for stationary accretion disks around black holes. In units of Eddington accretion rate defined as $10L_{\rm Edd}/c^2$, the accretion rates to which these solutions…

Astrophysics · Physics 2015-06-24 Feng Yuan

Based on no-outflow assumption, we investigate steady state, axisymmetric, optically thin accretion flows in spherical coordinates. By comparing the vertically integrated advective cooling rate with the viscous heating rate, we find that…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Wei-Min Gu

We present analytical and numerical solutions which describe a hot, viscous, two-temperature accretion flow onto a neutron star or any other compact star with a surface. We assume Coulomb coupling between the protons and electrons, and…

Astrophysics · Physics 2009-11-06 Mikhail V. Medvedev

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

Binney (2003) has argued that two-temperature radiatively inefficient accretion flow models are unphysical because the electron-ion equipartition time is much shorter than the accretion time. I show that this conclusion is incorrect because…

Astrophysics · Physics 2007-05-23 Eliot Quataert

Convection-dominated accretion flows (CDAF) are expected to have a shallower density profile and a higher radiation efficiency as compared to advection-dominated accretion flows (ADAF). Both solutions have been developed to account for the…

Astrophysics · Physics 2008-11-26 Myeong-Gu Park , Jeremiah P. Ostriker

In the innermost regions of low-luminosity accretion flows, including Sgr A* at the center of our Galaxy, the frequency of Coulomb collisions is so low that the plasma is two-temperature, with the ions substantially hotter than the…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Lorenzo Sironi

We present analytical and numerical solutions which describe a hot, viscous, two-temperature accretion flow onto a rotating neutron star or any other rotating compact star with a surface. We assume Coulomb coupling between the protons and…

Astrophysics · Physics 2009-11-06 Mikhail Medvedev , Ramesh Narayan

We present a numerical method which evolves a two-temperature, magnetized, radiative, accretion flow around a black hole, within the framework of general relativistic radiation magnetohydrodynamics. As implemented in the code KORAL, the gas…

High Energy Astrophysical Phenomena · Physics 2017-01-18 A. Sadowski , M. Wielgus , R. Narayan , D. Abarca , J. C. McKinney , A. Chael