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Related papers: Properties of accretion shock waves in viscous flo…

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Numerical simulations of MHD accretion flows in the vicinity of a supermasssive black hole provide important insights to the problem of why and how systems -- such as the Galactic Center -- are underluminous and variable. To access…

Astrophysics · Physics 2009-11-13 Monika Moscibrodzka , Daniel Proga , Bozena Czerny , Aneta Siemiginowska

We explore the effects of anisotropic thermal conduction, anisotropic pressure, and magnetic field strength on the hot accretion flows around black holes by solving the axisymmetric, steady-state magnetohydrodynamic equations. The…

High Energy Astrophysical Phenomena · Physics 2022-03-09 Amin Mosallanezhad , Fatemeh Zahra Zeraatgari , Liquan Mei , De-Fu Bu

In this proceeding, we provide a novel approach to study the General Relativistic Magnetohydrodynamic (GRMHD) accretion flows around rotating black holes (BHs). In doing so, we choose a sub-Keplerian distribution of angular momentum of the…

High Energy Astrophysical Phenomena · Physics 2025-03-11 Samik Mitra

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

We investigate the accretion process for different spherically symmetric space-time geometries for a static fluid. We analyse this procedure using the most general black hole metric ansatz. After that, we examine the accretion process for…

General Relativity and Quantum Cosmology · Physics 2015-10-30 Sebastian Bahamonde , Mubasher Jamil

In this work we would like to address the issue of shock formation in black hole accretion discs. We provide a {\it generalized two parameter solution scheme} for multi-transonic, accretion and wind around Schwarzschild black holes, by…

Astrophysics · Physics 2016-08-30 Tapas Kumar Das , Jayant K. Pendharkar , Sanjit Mitra

Spirals shocks have been widely studied in the context of galactic dynamics and protostellar discs. They may however also play an important role in some classes of close binary stars, and more particularly in cataclysmic variables. In this…

Astrophysics · Physics 2007-05-23 Henri M. J. Boffin

We obtain self-similar solutions that describe the dynamics of a self-gravitating, rotating, viscous system. We use simplifying assumptions; but explicitly include viscosity and the cooling due to the dissipation of energy. By assuming that…

Astrophysics · Physics 2009-11-07 Mohsen Shadmehri , Jamshid Ghanbari

Context. Many low-redshift active galactic nuclei harbor a supermassive black hole accreting matter at low or medium rates. At such rates, the accretion flow usually consists of a cold optically thick disk, plus a hot, low density,…

High Energy Astrophysical Phenomena · Physics 2021-05-19 Eduardo M. Gutiérrez , Florencia L. Vieyro , Gustavo E. Romero

The formation of massive black holes and their coevolution with host galaxies are pivotal areas of modern astrophysics. Spherical accretion onto a central point mass serves as a foundational framework in cosmological simulations,…

High Energy Astrophysical Phenomena · Physics 2025-09-04 Razieh Ranjbar , Héctor R. Olivares-Sánchez , Shahram Abbassi

The global structure of optically thin advection dominated accretion flows which are composed of two-temperature plasma around black holes is calculated. We adopt the full set of basic equations including the advective energy transport in…

Astrophysics · Physics 2009-10-30 T. Manmoto , S. Mineshige , M. Kusunose

Shock wave solutions in anisotropic relativistic hydrodynamics are considered. A new phenomenon of anisotropy-related angular deflection of the incident flow by the shock wave front is described. Patterns of velocity and momentum…

Nuclear Theory · Physics 2022-05-18 Aleksandr Kovalenko , Andrey Leonidov

We present simulation results examining the presence and behavior of standing shocks in zero-energy low angular momentum advective accretion flows and explore their (in)stabilities properties taking into account various specific angular…

High Energy Astrophysical Phenomena · Physics 2024-12-18 Jun-Xiang Huang , Chandra B. Singh

The topologies are obtained for accretion flows around black holes as the parameters, accretion rate and specific angular momentum are varied. Paczy{\'n}ski-Wiita pseudo-Newtonian potential is used to mimic the gravitational field of a…

Astrophysics · Physics 2009-09-29 Sivakumar G. Manickam

We study the stability of standing shock waves in advection-dominated accretion flows into a Schwarzschild black hole by 2D general relativistic hydrodynamic simulations as well as linear analysis in the equatorial plane. We demonstrate…

Astrophysics · Physics 2009-11-13 Hiroki Nagakura , Shoichi Yamada

We write down and solve equations describing steady state, optically thin, advection-dominated accretion onto a Kerr black hole. The mean flow, described by the relativistic fluid equations, is axisymmetric and vertically averaged. The…

Astrophysics · Physics 2009-10-30 Charles F. Gammie , Robert Popham

We analytically study how the behaviour of accretion flows changes when the flow model is varied. We study the transonic properties of the conical flow, a flow of constant height and a flow in vertical equilibrium and show that all these…

Astrophysics · Physics 2009-11-10 S. K. Chakrabarti , Santabrata Das

A large-scale closed magnetic field can transfer angular momentum and energy between a black hole (BH) and its surrounding accretion flow. We investigate the effects of this magnetic coupling (MC) process on the dynamics of a hot accretion…

Astrophysics · Physics 2009-11-13 R. Y. Ma , F. Yuan , D. X. Wang

Centrifugal barrier supported boundary layer (CENBOL) of a black hole affects the spectrum exactly in the same way the boundary layer of a neutron star does. The CENBOL is produced due to standing or oscillating shock waves and these shocks…

Astrophysics · Physics 2007-05-23 Samir Mandal , Sandip K. Chakrabarti

Accretion onto a supermassive black hole of a rotating inflow is a particularly difficult problem to study because of the wide range of length scales involved. There have been broadly utilized analytic and numerical treatments of the global…

Astrophysics of Galaxies · Physics 2015-06-05 Jason Li , Jeremiah Ostriker , Rashid Sunyaev