Structure of a hot accretion flow in the presence of outflow and convection with large ordered magnetic field

Abstract

Hydrodynamic and magnetohydrodynamic simulations of hot accretion flow have indicated that there is an inward decrease of mass accretion rate with decreasing radius. Consequently, we have a flatter density profile (ρ ∝ r-p with p ∝ 1.5-s in the case of M ∝ rs, 0 ≤ s < 1) compared to the case of a constant accretion rate (ρ ∝ r-3/2). In order to describe this behaviour, two models have been proposed: inflow-outflow solution and convection-dominated accretion flows. We have studied the properties of a hot accretion flow in the presence of convection, large-scale magnetic field and outflow. We have considered an axisymmetric viscous flow in the steady state. We used the self-similar solutions to solve the 1.5-dimensional inflow-outflow equations. We have assumed the convection as a free parameter in our model for simplicity. We have considered two components of magnetic field (toroidal and vertical) in this paper. We have shown that the strong convection makes the inflow accrete and rotate slower while it becomes hotter and thicker. We have found that the thickness of the disc deviates from non-convective solutions obviously. We have also shown that two components of magnetic field have the opposite effects on the thickness of the disc and similar effects on the radial and angular velocities of the flow.