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Related papers: Spherical Accretion with Anisotropic Thermal Condu…

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Outward transport of angular momentum, as well as viscous and thermal stability, are the necessary criteria for the formation of accretion disc and to radiate steadily. Turbulent motions originating from magneto-rotational instability or…

High Energy Astrophysical Phenomena · Physics 2022-05-18 Sudeb Ranjan Datta , Tushar Mondal , Banibrata Mukhopadhyay

Differentially rotating, "advection-dominated" accretion flows are considered in which the heat generated by viscous dissipation is retained in the fluid. The equations of time-dependent quasi-spherical accretion are solved in a simplified…

Astrophysics · Physics 2009-10-31 G. I. Ogilvie

Spherical accretion flows are simple enough for analytical study, by solution of the corresponding fluid dynamic equations. The solutions of stationary spherical flow are due to Bondi. The questions of the choice of a physical solution and…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Jose Gaite

The properties of accretion flows are affected by the angular momentum of the accreting gas. M.-G. Park found that the mass accretion rate, specifically, decreases significantly as the gas angular momentum increases. However, R. Narayan &…

Astrophysics of Galaxies · Physics 2026-01-13 Dongho Han , Myeong-Gu Park

The standard thin disk model predicts that when the accretion rate is over a small fraction of the Eddington rate, which corresponds to $L \ga 0.06 L_{Edd}$, the inner region of the disk is radiation-pressure-dominated and thermally…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Sheng-Ming Zheng , Feng Yuan , Wei-Min Gu , Ju-Fu Lu

(abridged) AIMS. We investigate the dynamics and stability of post-shock plasma streaming along nonuniform stellar magnetic fields at the impact region of accretion columns. We study how the magnetic field configuration and strength…

Solar and Stellar Astrophysics · Physics 2015-06-17 S. Orlando , R. Bonito , C. Argiroffi , F. Reale , G. Peres , M. Miceli , T. Matsakos , C. Stehlé , L. Ibgui , L. de Sá , J. P. Chièze , T. Lanz

We present an implementation of thermal conduction including the anisotropic effects of magnetic fields for SPH. The anisotropic thermal conduction is mainly proceeding parallel to magnetic fields and suppressed perpendicular to the fields.…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-18 Alexander Arth , Klaus Dolag , Alexander M. Beck , Margarita Petkova , Harald Lesch

We examine the role of thermal conduction and magnetic fields in cores of galaxy clusters through global simulations of the intracluster medium (ICM). In particular, we study the influence of thermal conduction, both isotropic and…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-29 Baban Wagh , Prateek Sharma , Michael McCourt

We investigate spherical accretion to a rotating magnetized star in the "propeller" regime using axisymmetric resistive magnetohydrodynamic simulations. The regime is predicted to occur if the magnetospheric radius is larger than the…

Astrophysics · Physics 2007-05-23 O. D. Toropina , M. M. Romanova , R. V. E. Lovelace

This paper investigates the effects of saturated thermal conduction (TC) and thermal-driven winds (TDWs) on magnetized advection-dominated accretion onto a rotating black hole (BH). We incorporate dissipative processes in the magnetized…

High Energy Astrophysical Phenomena · Physics 2025-01-20 Biplob Sarkar , Indu Kalpa Dihingia , Ranjeev Misra

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

By taking into account the effect of toroidal magnetic field and its correspond heating, we determine the thickness of advection-dominated accretion flows. We consider an axisymetric, rotating, steady viscous-resistive, magnetized accretion…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Maryam Samadi , Shahram Abbassi , Mahdi Khajavi

Bondi accretion assumes that there is a sink of mass at the center -- which in case of a black hole (BH) corresponds to the advection of matter across the event horizon. Other stars, such as a neutron star (NS), have surfaces and hence the…

High Energy Astrophysical Phenomena · Physics 2016-08-09 Prasun Dhang , Prateek Sharma , Banibrata Mukhopadhyay

We investigate two-temperature accretion flows onto strongly magnetized compact stars. Matter is accreted in the form of an accretion disc upto the disc radius ($r_{\rm d}$), where, the magnetic pressure exceeds both the gas and ram…

High Energy Astrophysical Phenomena · Physics 2023-04-19 Shilpa Sarkar , Kuldeep Singh , Indranil Chattopadhyay , Philippe Laurent

We use Chandra X-ray data and Very Large Array radio observations for a sample of 20 nearby, massive, X-ray bright, early-type galaxies to investigate the relation between the Bondi accretion rates and the mechanical jet powers. We find a…

High Energy Astrophysical Phenomena · Physics 2022-10-12 Tomáš Plšek , Norbert Werner , Romana Grossová , Martin Topinka , Aurora Simionescu , Steve W. Allen

AIMS. We investigate the stability and dynamics of accretion shocks in CTTSs, considering the case of beta >= 1 in the post-shock region. In these cases the 1D approximation is not valid and a multi-dimensional MHD approach is necessary.…

Solar and Stellar Astrophysics · Physics 2015-05-14 S. Orlando , G. G. Sacco , C. Argiroffi , F. Reale , G. Peres , A. Maggio

We present a self-consistent, bimodal stationary solution for spherically symmetric flows driven by young massive stellar clusters with a central supermassive black hole. We demonstrate that the hydrodynamic regime of the flow depends on…

Observed accretion rates onto the Milky-Way and other local spirals fall short of that required to sustain star formation for cosmological timescales. A potential avenue for this unseen accretion is an inflow in the volume-filling hot phase…

In this paper we investigate how convective instabilities influence heat conduction in the intracluster medium (ICM) of cool-core galaxy clusters. The ICM is a high-beta, weakly collisional plasma in which the transport of momentum and heat…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Henrik N. Latter , Matthew W. Kunz

The Bondi-Hoyle formula gives the approximate accretion rate onto a point particle accreting from a uniform medium. However, in many situations accretion onto point particles occurs from media that are turbulent rather than uniform. In this…

Astrophysics · Physics 2008-11-26 Mark R. Krumholz , Christopher F. McKee , Richard I. Klein