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Related papers: Exact analytical solutions for ADAFs

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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

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

We solve the two-dimensional hydrodynamic equations of hot accretion flow in the presence of the thermal conduction. The flow is assumed to be in steady-state and axisymmetric, and self-similar approximation is adopted in the radial…

High Energy Astrophysical Phenomena · Physics 2021-03-24 Amin Mosallanezhad , Fatemeh Zahra Zeraatgari , Liquan Mei , De-Fu Bu

We implement a new semi-analytical approach to investigate radially self-similar solutions for the steady-state advection-dominated accretion flows (ADAFs). We employ the usual $\alpha$-prescription for the viscosity and all the components…

High Energy Astrophysical Phenomena · Physics 2018-08-08 Asiyeh Habibi , Shahram Abbassi , Mohsen Shadmehri

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

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

In a previous paper, we described new analytic formulae for optically-thick supercritical accretion flows (Watarai 2006, hereafter paper 1). Here we present analytic formulae for optically-thin one-temperature accretion flows including the…

Astrophysics · Physics 2015-06-24 Ken-ya Watarai

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

Two Component Advective Flow is the only complete solution that incorporates outcomes of actual theoretical solutions to explain spectral and timing properties of radiation emitted from the vicinity of black holes. It redefined the subject…

High Energy Astrophysical Phenomena · Physics 2015-09-03 Sandip Kumar Chakrabarti

All high temperature accretion solutions including ADAF are physically thick, so outgoing radiation interacts with the incoming flow, sharing as much or more resemblance with classical spherical accretion flows as with disk flows. We…

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

We solved analytically viscous two-dimensional (2D) fluid equations for accretion and outflows in spherical polar coordinates ($r, \theta, \phi$) and obtained explicitly flow variables in $r-$ and $\theta -$directions around black holes…

High Energy Astrophysical Phenomena · Physics 2018-07-04 Rajiv Kumar , Wei-Min Gu

We present solutions to the accretion disk structure equations in which advective cooling is accounted for in a self-consistent way. It is shown that for high rates of accretion, above a critical value, when without advection there are no…

Astrophysics · Physics 2007-05-23 I. V. Artemova , G. S. Bisnovatyi-Kogan , G. Bjornsson , I. Novikov

Observations and numerical magnetohydrodynamic (MHD) simulations indicate the existence of outflows and ordered large-scale magnetic fields in the inner region of hot accretion flows. In this paper we present the self-similar solutions for…

Astrophysics · Physics 2009-11-13 De-Fu Bu , Feng Yuan , Fu-Guo Xie

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 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 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 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

When we model black hole accretion sources such as active galactic nuclei and black hole X-ray binaries as advection-dominated accretion flows (ADAFs), it is neccesary to use the global solution to the equations rather than the simpler…

Astrophysics · Physics 2009-11-13 Feng Yuan , Renyi Ma , Ramesh Narayan

Using simple arguments we show that the canonical thin keplerian accretion disks cannot smoothly match any plain advection dominated flow (ADAF) model. By 'plain' ADAF model we mean the ones with zero cooling. The existence of sonic points…

Astrophysics · Physics 2016-08-30 D. Molteni , G. Gerardi , M. A. Valenza
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