Backflow in simulated MHD accretion disks

TL;DR

This paper investigates backflow phenomena in resistive MHD simulations of accretion disks around magnetized stars, revealing the influence of magnetic fields and resistivity on flow patterns and stagnation points.

Contribution

It introduces resistive MHD simulations of accretion disks with magnetic fields, highlighting the effects of magnetic strength and resistivity on backflow behavior.

Findings

Backflow occurs with strong magnetic fields and high resistivity.

The stagnation radius differs between magnetic and hydrodynamic cases.

Backflow exhibits non-stationary behavior in magnetic scenarios.

Abstract

We perform resistive MHD simulations of accretion disk with alpha-viscosity, accreting onto a rotating star endowed with a magnetic dipole. We find backflow in the presence of strong magnetic field and large resistivity, and probe for the dependence on Prandtl number. We find that in the magnetic case the distance from the star at which backflow begins, the stagnation radius, is different than in the hydrodynamic case, and the backflow shows non-stationary behavior. We compare the results with hydrodynamics simulations.