Manifestations of the Galactic Center Magnetic Field

TL;DR

This paper reviews evidence for a strong, ordered magnetic field in the Galactic Center's molecular zone, highlighting its structure, interactions, and implications for galactic activity and outflows.

Contribution

It synthesizes observational evidence to characterize the magnetic field configurations and discusses their potential roles in galactic dynamics and energetics.

Findings

Presence of a predominantly parallel magnetic field within dense clouds.

Existence of vertical, synchrotron-emitting filamentary magnetic features.

Magnetic fields influence gas flow and energetic particle dynamics in the Galactic Center.

Abstract

Several independent lines of evidence reveal that a relatively strong and highly ordered magnetic field is present throughout the Galaxy's central molecular zone (CMZ). The field within dense clouds of the central molecular zone is predominantly parallel to the Galactic plane, probably as a result of the strong tidal shear in that region. A second magnetic field system is present outside of clouds, manifested primarily by a population of vertical, synchrotron-emitting filamentary features aligned with the field. Whether or not the strong vertical field is uniform throughout the CMZ remains undetermined, but is a key central issue for the overall energetics and the impact of the field on the Galactic center arena. The interactions between the two field systems are considered, as they are likely to drive some of the activity within the CMZ. As a proxy for other gas-rich galaxies in the local group and beyond, the Galactic center region reveals that magnetic fields are likely to be an important diagnostic, if not also a collimator, of the flow of winds and energetic particles out of the nucleus.