Identifying relationships between galactic magnetic fields and the interstellar medium

Abstract

Magnetic fields are present throughout galaxies, permeating the interstellar medium (ISM). However, there is much that is not known about the relationships between these magnetic fields and the other components of the ISM, such as atomic and molecular gas. The goal of my work was to identify relationships between parameters that characterize the magnetic fields in galaxies and parameters that characterize the ISM. For a sample of 20 spiral galaxies, I collected data for these parameters from the published literature. With these data, I was able to identify 5 correlations between magnetic field parameters and ISM parameters, one of which had been previously observed and 4 that have not yet been reported. I was also able to test the predictions of dynamo theory models with the observed magnetic field parameters; I found that only the magnetic helicity balance model was able to predict the observed behaviour.