Magnetic-Field Structure in the Accretion Disks of Semi-Detached Binary Systems

TL;DR

This study uses 3D MHD simulations to analyze magnetic field structures in accretion disks of semi-detached binary systems, highlighting the formation of toroidal magnetic zones and their potential observational signatures.

Contribution

It introduces a detailed simulation approach considering dipolar magnetic fields and turbulent diffusion, revealing new insights into magnetic structures and dynamics in accretion disks.

Findings

Intense generation of toroidal magnetic fields in the disk

Formation of magnetic zones separated by current sheets

Potential for quasi-periodic accretion rate oscillations

Abstract

The results of three-dimensional MHD numerical simulations are used to investigate the characteristic properties of the magnetic-field structures in the accretion disks of semi-detached binary systems. It is assumed that the intrinsic magnetic field of the accretor star is dipolar. Turbulent diffusion of the magnetic field in the disk is taken into account. The SS Cyg system is considered as an example. The results of the numerical simulations show the intense generation of a predominantly toroidal magnetic field in the accretion disk. Magnetic zones with well defined structures for the toroidal magnetic field form in the disk, which are separated by current sheets in which there is magnetic reconnection and current dissipation. Possible observational manifestations of such structures are discussed. It is shown that the interaction of a spiral precessional wave with the accretor's magnetosphere could lead to quasi-periodic oscillations of the accretion rate.