Galactic dynamo simulations

TL;DR

This paper presents detailed simulations of galactic dynamos driven by supernova turbulence, demonstrating a relatively rapid growth time and comparing results with magneto-rotational instability models.

Contribution

It provides new insights into the scaling of the galactic dynamo effect and links simulation results with mean-field models and other instability simulations.

Findings

Dynamo growth time is approximately 200 million years.

Simulation results support the existence of a large-scale galactic dynamo.

Comparison with magneto-rotational instability simulations shows consistent behavior.

Abstract

Recent simulations of supernova-driven turbulence within the ISM support the existence of a large-scale dynamo. With a growth time of about two hundred million years, the dynamo is quite fast -- in contradiction to many assertions in the literature. We here present details on the scaling of the dynamo effect within the simulations and discuss global mean-field models based on the adopted turbulence coefficients. The results are compared to global simulations of the magneto-rotational instability.