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The present study examines self-similarity evolution of advection dominated accretion flow (ADAF) in the presence of a toroidal magnetic field. In this research, it was assumed that the angular momentum transport is due to viscous…

High Energy Astrophysical Phenomena · Physics 2012-05-11 Alireza Khesali , Kazem Faghei

Observational evidence and theoretical arguments postulate that outflows may play a significant role in the advection-dominated accretion discs (ADAFs). While the azimuthal viscosity is the main focus of most previous studies in this…

High Energy Astrophysical Phenomena · Physics 2020-03-18 S. M. Ghoreyshi , M. Shadmehri

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

A model for advection-dominated accretion flows (ADAFs) in a global magnetic field is proposed. In contrast to the well known ADAF models in which the viscosity of a fluid determines both angular momentum transfer and energy dissipation in…

Astrophysics · Physics 2009-10-31 Osamu Kaburaki

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 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

In this paper, the self-similar solution of resistive advection dominated accretion flows (ADAF) in the presence of a pure azimuthal magnetic field is investigated. The mechanism of energy dissipation is assumed to be the viscosity and the…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Kazem Faghei

The standard Advection-Dominated Accretion Flow (ADAF) is studied using a set of self-similar analytical solutions in the spherical coordinates. Our new solutions are useful for studying ADAFs without dealing with the usual mathematical…

High Energy Astrophysical Phenomena · Physics 2015-06-19 Mohsen Shadmehri

The effects of outflow on the behavior of a viscous gaseous disc around a compact object in an advection-dominated state are examined in this paper. We suppose that the flow is steady, axisymmetric, and rotating. Also, we focus on the model…

High Energy Astrophysical Phenomena · Physics 2025-05-06 Fahimeh Habibi

Recent numerical simulations of radiatively inefficient accretion flows onto compact objects have shown that convection is a general feature in such flows. Dissipation of rotational and gravitational energies in the accretion flows results…

Astrophysics · Physics 2009-11-06 Igor V. Igumenshchev , Marek A. Abramowicz

We consider height-integrated equations of an advection-dominated accretion flow (ADAF), assuming that there is no mass outflow. We include convection through a mixing length formalism. We seek self-similar solutions in which the rotational…

Astrophysics · Physics 2009-10-31 Ramesh Narayan , Igor V. Igumenshchev , Marek A. Abramowicz

We show that recently published assertions that advection dominated accretion flows (ADAFs) require the presence of strong winds are unfounded because they assume that low radiative efficiency in flows accreting at low rates onto black…

Astrophysics · Physics 2007-05-23 Marek A. Abramowicz , Jean-Pierre Lasota , Igor V. Igumenshchev

We carry out the self-similar solutions of viscous-resistive accretion flows around a magnetized compact object. We consider an axisymmetric, rotating, isotheral steady accretion flow which contains a poloidal magnetic field of the central…

Astrophysics · Physics 2012-06-19 J. Ghanbari , F. Salehi , S. Abbassi

We examine the effects of a hydrodynamical wind on advection dominated accretion flows with thermal conduction in the presence of a toroidal magnetic field under a self-similar treatment. The disk gas is assumed to be isothermal. For a…

Astrophysics of Galaxies · Physics 2010-12-16 S. Abbassi , J. Ghanbari , M. Ghasemnezhad

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

We have studied the effects of thermal conduction on the structure of viscous and resistive advection-dominated accretion flows (ADAFs). The importance of thermal conduction on hot accretion flow is confirmed by observations of hot gas that…

High Energy Astrophysical Phenomena · Physics 2012-05-11 Kazem Faghei

A self-similar solution for time evolution of quasi-spherical, self-gravitating accretion flows is obtained under the assumption that the generated heat by viscosity is retained in the flow. The solutions are parameterized by the ratio of…

Astrophysics · Physics 2009-11-10 Mohsen Shadmehri

A model for axisymmetric magnetized accretion flow is proposed. The dominant mechanism of energy dissipation is assumed to be the magnetic diffusivity due to turbulence in the accretion flow. In analogy to the advection-dominated accretion…

Astrophysics · Physics 2009-11-07 Mohsen Shadmehri

In this Letter we investigate the properties of advection-dominated accretion flows (ADAFs) fed by the evaporation of a Shakura-Sunyaev accretion disk (SSD). In our picture the ADAF fills the central cavity evacuated by the SSD and extends…

Astrophysics · Physics 2009-10-31 R. Turolla , C. P. Dullemond

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

High Energy Astrophysical Phenomena · Physics 2015-05-13 J. Ghanbari , S. Abbassi , M. Ghasemnezhad
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