Cosmic ray driven dynamo in barred and ringed galaxies

TL;DR

This study demonstrates that cosmic ray driven dynamo processes can amplify magnetic fields in barred and ringed galaxies within a few billion years, producing magnetic configurations similar to observed polarized radio emissions.

Contribution

It introduces a cosmic ray driven dynamo model that accounts for magnetic field amplification and configuration in barred and ringed galaxies, aligning with observational data.

Findings

Magnetic fields are amplified to a few microGauss within a few Gyr.

Magnetic field configurations resemble observed polarized radio maps.

CR driven dynamo effectively explains magnetic structures in complex galaxy types.

Abstract

We study the global evolution of the magnetic field and interstellar medium (ISM) of the barred and ringed galaxies in the presence of non-axisymmetric components of the potential, i.e. the bar and/or the oval perturbations. The magnetohydrodynamical dynamo is driven by cosmic rays (CR), which are continuously supplied to the disk by supernova (SN) remnants. Additionally, weak, dipolar and randomly oriented magnetic field is injected to the galactic disk during SN explosions. To compare our results directly with the observed properties of galaxies we construct realistic maps of high-frequency polarized radio emission. The main result is that CR driven dynamo can amplify weak magnetic fields up to few $\mu$G within few Gyr in barred and ringed galaxies. What is more, the modelled magnetic field configuration resembles maps of the polarized intensity observed in barred and ringed galaxies.