English
Related papers

Related papers: Self-Similar Solutions for Viscous and Resistive A…

200 papers

We consider axisymmetric viscous accretion flows where a fraction f of the viscously dissipated energy is advected with the accreting gas as stored entropy and a fraction 1-f is radiated. When f is small (i.e. very little advection), our…

Astrophysics · Physics 2009-10-22 Ramesh Narayan , Insu Yi

The main aim of this paper is studying the effect of toroidal magnetic field on the structure of Advection-Dominated Accretion Flows (ADAF) in the presence of the turbulence viscosity and diffusivity due to viscosity and magnetic field…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Amin Mosallanezhad , Shahram Abbassi , Nasim Beiranvand

We present the basic equations and sample solutions for the steady-state global transonic solutions of the advection-dominated accretion flows (ADAFs) with a causal viscosity prescription. The procedures for the stable numerical…

Astrophysics · Physics 2009-06-23 Rohta Takahashi

Using mean field MHD, we discuss the energetics of optically thin, two temperature, advection-dominated accretion flows (ADAFs). If the magnetic field is tangled and roughly isotropic, flux freezing is insufficient to maintain the field in…

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

We investigate the dependency of the inflow-wind structure of the hot accretion flow on the kinematic viscosity coefficient. In this regard, we propose a model for the kinematic viscosity coefficient to mimic the behavior of the…

High Energy Astrophysical Phenomena · Physics 2021-09-15 Fatemeh Zahra Zeraatgari , Liquan Mei , Amin Mosallanezhad

We numerically solve the set of dynamical equations describing advection-dominated accretion flows (ADAF) around black holes, using a method similar to that of Chakrabarti (1996a). We choose the sonic radius of the flow $R_s$ and the…

Astrophysics · Physics 2009-10-31 Ju-Fu Lu , Wei-Min Gu , Feng Yuan

We solve the set of hydrodynamic (HD) equations for optically thin Advection Dominated Accretion Flows (ADAFs) by assuming radially self-similar in spherical coordinate system $ (r, \theta, \phi) $. The disk is considered to be steady state…

High Energy Astrophysical Phenomena · Physics 2015-11-12 Fateme Zahra Zeraatgari , Shahram Abbassi

Force due to the self-gravity of the disc in the vertical direction is considered to study its possible effects on the structure of a magnetized advection-dominated accretion disc. We present steady-sate self similar solutions for the…

High Energy Astrophysical Phenomena · Physics 2015-05-30 A. Mosallanezhad , S. Abbassi , M. Shadmehri , J. Ghanbari

In the present study time evolution of quasi-spherical polytropic accretion flow with toroidal magnetic field is investigated. The study especially focused the astrophysically important case in which the adiabatic exponent $\gamma=5/3$. In…

Astrophysics · Physics 2012-05-11 Alireza Khesali , Kazem Faghei

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

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

We consider viscous rotating accretion flows in which most of the viscously dissipated energy is stored as entropy rather than being radiated. Such advection-dominated flows may occur when the optical depth is either very small or very…

Astrophysics · Physics 2009-10-22 Ramesh Narayan , Insu Yi

Time evolution of advection-dominated accretion flow (ADAF) around a rotating compact object is presented. The equations of time-dependent of fluid including the Coriolis force along with the centrifugal and pressure gradient forces are…

High Energy Astrophysical Phenomena · Physics 2020-10-14 Fahimeh Habibi

We present a systematic, analytical study of geometrically thin, optically thick accretion disc solutions for magnetized turbulent flows, with an alpha-like viscosity prescription. Under the only assumptions that (1) Magneto-Rotational…

Astrophysics · Physics 2009-11-07 A. Merloni

Accretion disks are three-dimensional, turbulent, often self-gravitating, magnetohydrodynamic flows, which can be modeled in detail with numerical simulations. In this paper, we present a new algorithm that is based on a spectral…

Astrophysics · Physics 2009-07-22 Chi-kwan Chan , Dimitrios Psaltis , Feryal Ozel

We investigate the properties of a hot accretion flow bathed in a poloidal magnetic field. We consider an axisymmetric viscous resistive flow in the steady state configuration. We assume the dominant mechanism of energy dissipation is due…

High Energy Astrophysical Phenomena · Physics 2017-08-30 Maryam Samadi , Shahram Abbassi

Hydrodynamics and magnetohydrodynamic simulations of hot accretion flow have indicated that there is an inward decreasing of mass accretion rate with decreasing radius. Consequently, we have a flatter density profile ($\rho \propto r^{-p}$…

High Energy Astrophysical Phenomena · Physics 2017-06-12 Maryam Ghasemnezhad

We provide a 2.5-dimensional solution to a complete set of viscous hydrodynamical equations describing accretion-induced outflow and then plausible jet around black holes/compact objects. We prescribe a self-consistent advective…

Astrophysics · Physics 2009-11-13 Shubhrangshu Ghosh , Banibrata Mukhopadhyay

We present the effect of a hydrodynamical wind on the structure and the surface temperature of a vertically self-gravitating magnetized ADAFs using self-similar solutions. Also a model for an axisymmetric, steady-state, vertically…

High Energy Astrophysical Phenomena · Physics 2016-03-30 Maryam Ghasemnezhad , Shahram Abbassi

By taking into account photon absorption, we investigate the vertical structure of accretion flows with comparable radiation and gas pressures. We consider two separate energy equations for matter and radiation in the diffusion limit. In…

High Energy Astrophysical Phenomena · Physics 2019-08-10 Maryam Samadi , Shahram Abbassi , Wei-Min Gu