Viscoresistive MHD Configurations of Plasma in Accretion Disks

TL;DR

This paper explores the equilibrium configurations of magnetized accretion disks using a viscoresistive MHD model, revealing how dissipative effects influence magnetic structure and disk morphology.

Contribution

It introduces a generalized viscoresistive MHD framework that integrates dissipative plasma properties with angular momentum transport in accretion disks.

Findings

Magnetic flux surfaces are altered by dissipative effects.

The model analytically describes linear and non-linear equilibrium features.

Additional currents and fluxes modify disk magnetic morphology.

Abstract

We present a discussion of two-dimensional magneto-hydrodynamics (MHD) configurations, concerning the equilibria of accretion disks of a strongly magnetized astrophysical object. We set up a viscoresistive scenario which generalizes previous two-dimensional analyses by reconciling the ideal MHD coupling of the vertical and the radial equilibria within the disk with the standard mechanism of the angular momentum transport, relying on dissipative properties of the plasma configuration. The linear features of the considered model are analytically developed and the non-linear configuration problem is addressed, by fixing the entire disk profile at the same order of approximation. Indeed, the azimuthal and electron force balance equations are no longer automatically satisfied when poloidal currents and matter fluxes are included in the problem. These additional components of the equilibrium configuration induce a different morphology of the magnetic flux surface, with respect to the ideal and simply rotating disk.