Resistive Hot Accretion Flows with Anisotropic Pressure

TL;DR

This paper investigates how resistive dissipation and anisotropic pressure influence the dynamics and temperature of hot accretion flows, providing insights into phenomena like flares in Galactic Center Sgr A* through self-similar solutions.

Contribution

It introduces self-similar solutions for resistive hot accretion flows considering anisotropic pressure, highlighting the effects on flow velocities and heating mechanisms.

Findings

Radial and rotational velocities increase with anisotropic pressure.

Resistive heating can account for up to 10% of total heating at certain anisotropic pressures.

Higher anisotropic pressure reduces resistive heating contribution.

Abstract

Since the collisional mean free path of charged particles in hot accretion flows can be significantly larger than the typical length-scale of the accretion flows, the gas pressure is anisotropic to magnetic field lines. For such a large collisional mean free path, the resistive dissipation can also play a key role in hot accretion flows. In this paper, we study the dynamics of resistive hot accretion flows in the presence of anisotropic pressure. We present a set of self-similar solutions where the flow variables are assumed to be a function only of radius. Our results show that the radial and rotational velocities and the sound speed increase considerably with the strength of anisotropic pressure. The increase in infall velocity and in sound speed are more significant if the resistive dissipation is taken into account. We find that such changes depend on the field strength. Our results indicate that the resistive heating is $10\%$ of the heating by the work done by anisotropic pressure when the strength of anisotropic pressure is 0.1. This value becomes higher when the strength of anisotropic pressure reduces. The increase in disk temperature can lead to heating and acceleration of the electrons in such flows. It helps us to explain the origin of phenomena such as the flares in Galactic Center Sgr A*.