Ring sequence decomposition of an accretion disk: the viscoresistive approach

TL;DR

This paper develops a viscoresistive MHD model for thin accretion disks, revealing a ring-like matter distribution pattern through radial oscillations, integrating microscopic and macroscopic features of astrophysical systems.

Contribution

It introduces a comprehensive equilibrium model for accretion disks that includes dissipative effects, poloidal fluxes, and magnetic fields, enabling detailed radial and vertical structure analysis.

Findings

Identification of ring-like matter distribution in accretion disks.

Demonstration of radial oscillations in matter flux.

Full equilibrium profiles including azimuthal momentum and electron force balance.

Abstract

We analyze a two dimensional viscoresistive magnetohydrodynamical (MHD) model for a thin accretion disk which reconciles the crystalline structure outlined in [Coppi(2005), Coppi and Rousseau(2006)] with real microscopic and macroscopic features of astrophysical accreting systems. In particular, we consider small dissipative effects (viscosity and resistivity, characterized by a magnetic Prandtl number of order unity), poloidal matter fluxes and a toroidal component of the magnetic field. These new ingredients allow us to set up the full equilibrium profile including the azimuthal component of the momentum conservation equation and the electron force balance relation. These two additional equations, which were identically satisfied in the original model, permit us to deal with non-zero radial and vertical matter fluxes, and the solution we construct for the global equilibrium system provides a full description of the radial and vertical dependence within the plasma disk. The main issue of our analysis is outlining a modulation of the matter distribution in the disk which corresponds to the formation of a ring-like sequence, here associated with a corresponding radial oscillation of the matter flux.