Viscous and resistive accretion flows with radially self-similar and outflows

TL;DR

This paper investigates the effects of resistivity, magnetic fields, and outflows on accretion disk dynamics using self-similar solutions, revealing how these factors influence the disk's rotation, temperature, and density.

Contribution

It introduces a self-similar model of accretion flows incorporating variable resistivity, magnetic fields, and outflows, providing new insights into their combined effects on disk properties.

Findings

Stronger outflows lead to faster rotation and cooler disks.

Adding magnetic diffusivity decreases surface density and rotational velocity.

Magnetic fields increase disk temperature and thickness.

Abstract

The existence of outflow in accretion flows is confirmed by observations and magnetohydrodynamics (MHD) simulations. In this paper, we study outflows of accretion flows in the presence of resistivity and toroidal magnetic field. The mechanism of energy dissipation in the flow is assumed to be the viscosity and the magnetic diffusivity due to turbulence in the accretion flow. It is also assumed that the magnetic diffusivity and the kinematic viscosity are not constant and vary by position and $\alpha$-prescription is used for them. The influence of outflow emanating from accretion disc is considered as a sink for mass, angular momentum and energy. The self-similar method is used to solve the integrated equations that govern the behavior of the accretion flow in the presence of outflow. The solutions represent the disc which rotates faster and becomes cooler for stronger outflows. Moreover, by adding the magnetic diffusivity, the surface density and rotational velocity decrease, while the radial velocity and temperature increase. The study of present model with the magnitude of magnetic field implies that the disc rotates and accretes faster and becomes hotter, while the surface density decreases. The disc thickness increases by adding the magnetic field or resistivity, while it becomes thinner for more losses of mass and energy due to the outflows.