Magnetically-levitating disks around supermassive black holes

TL;DR

This study models the formation of magnetically-levitating accretion disks around supermassive black holes, revealing magnetic support, stability, and implications for black hole growth.

Contribution

It introduces a numerical model of magnetically-supported disks formed from tidally disrupted magnetized gas clouds, highlighting magnetic pressure's role in stability and accretion.

Findings

Disks are supported by magnetic pressure against gravity.

Magnetic fields exhibit stable large-scale ordered geometry.

High magnetic pressure promotes high accretion rates and prevents fragmentation.

Abstract

In this paper we report on the formation of magnetically-levitating accretion disks around supermassive black holes. The structure of these disks is calculated by numerically modelling tidal disruption of magnetized interstellar gas clouds. We find that the resulting disks are entirely supported by the pressure of the magnetic fields against the component of gravitational force directed perpendicular to the disks. The magnetic field shows ordered large-scale geometry that remains stable for the duration of our numerical experiments extending over 10% of the disk lifetime. Strong magnetic pressure allows high accretion rate and inhibits disk fragmentation. This in combination with the repeated feeding of manetized molecular clouds to a supermassive black hole yields a possible solution to the long-standing puzzle of black hole growth in the centres of galaxies.