Self-Similar Solution of Hot Accretion Flows with Ordered Magnetic Field and Outflow

TL;DR

This paper derives self-similar solutions for hot accretion flows incorporating ordered magnetic fields and outflows, revealing significant impacts on flow dynamics and temperature, aligning with observational indications.

Contribution

It introduces a novel self-similar model for magnetized ADAFs with outflows, considering strong toroidal and vertical magnetic components, extending prior canonical models.

Findings

Magnetic fields lower the flow temperature.

Stronger magnetic fields increase rotational velocity.

Outflows significantly alter accretion flow properties.

Abstract

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 advection-dominated accretion flows (ADAFs) with outflows and ordered magnetic fields. Stimulated by numerical simulations, we assume that the magnetic field has a strong toroidal component and a vertical component in addition to a stochastic component. We obtain the self-similar solutions to the equations describing the magnetized ADAFs, taking into account the dynamical effects of the outflow. We compare the results with the canonical ADAFs and find that the dynamical properties of ADAFs such as radial velocity, angular velocity and temperature can be significantly changed in the presence of ordered magnetic fields and outflows. The stronger the magnetic field is, the lower the temperature of the accretion flow will be, and the faster the flow rotates. The relevance to observations is briefly discussed.