Particle Heating in Advection-dominated Accretion Flows
نویسنده
چکیده
I review particle heating by MHD turbulence in collision-less plasmas appropriate to advection-dominated accretion flows. These considerations suggest that the preferential turbulent heating of protons assumed by theoretical models is only achieved for relatively subthermal magnetic fields.
منابع مشابه
A Simplified Solution for Advection Dominated Accretion Flows with Outflow
The existence of outflow in the advection dominated accretion flows has been confirmed by both numerical simulations and observations. The outow models for ADAF have been investigated by several groups with a simple self similar solution. But this solution is inaccurate at the inner regions and can not explain the emitted spectrum of the flow; so, it is necessary to obtain a global solution for...
متن کاملTurbulence and Particle Heating in Advection-Dominated Accretion Flows
We extend and reconcile recent work on turbulence and particle heating in advection-dominated accretion flows. For approximately equipartition magnetic fields, the turbulence primarily heats the electrons. For weaker magnetic fields, the protons are primarily heated. The division between electron and proton heating occurs between β ∼ 5 and β ∼ 100 (β ≡ ratio of gas to magnetic pressure), depend...
متن کامل2 v 1 1 0 M ar 1 99 8 Turbulence and Particle Heating in Advection - Dominated Accretion Flows
We extend and reconcile recent work on turbulence and particle heating in advection-dominated accretion flows. For approximately equipartition magnetic fields, the turbulence primarily heats the electrons. For weaker magnetic fields, the protons are primarily heated. The division between electron and proton heating occurs between β ∼ 5 and β ∼ 100 (β ≡ ratio of gas to magnetic pressure), depend...
متن کاملOn the Energetics of Advection-Dominated Accretion Flows
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 equipartition with the gas. In this case, we expect a fraction of the energy generated by shear in the flow to be used to build up the magnetic field strengt...
متن کاملThe Role of Thermal Conduction in Accretion Disks with Outflows
In this work we solve the set of hydrodynamical equations for accretion disks in the spherical coordinates (r,θ,ϕ) to obtain the explicit structure along θ direction. We study a two-dimensional advective accretion disc in the presence of thermal conduction. We find self-similar solutions for an axisymmetric, rotating, steady, viscous-resistive disk. We show that the global structure of an advec...
متن کامل