Polarization and magnetization in the Galactic Center Radio Arc non-thermal filaments

The center of the Milky Way, known as the Galactic Center (GC), is an environment characterized by high molecular temperatures and densities and whose relative proximity to Earth makes it a valuable probe of more distant galactic nuclear regions. Unique, thread-like structures, known as non-thermal filaments (NTFs), are observed in the GC. Their non-thermal nature indicates they are tracing ordered magnetic field lines. A comprehensive analysis of these structures can probe the nature of the magnetic field in the GC. The most prominent of these NTFs, known as the Radio Arc, is an optimal candidate for such an analysis. We use the Very Large Array, a collection of 27 individual radio telescopes, to study the frequency-dependence of the emission from the Radio Arc. We first show the total and polarized intensity distributions of the Radio Arc, revealing smooth total intensity and discontinuous polarized intensity distributions. There is clear evidence of frequency-dependent depolarization occurring (likely caused by internal properties of the Radio Arc) and there is a population of elongated polarized structures which are oriented perpendicular to the extent of the Radio Arc. We analyze the change in the polarization angle as a function of frequency in order to determine the intrinsic magnetic field of the source. This field has an orientation which alternates between being parallel and rotated with respect to the Radio Arc. We also analyze the geometry of structures local to the Radio Arc to assist in our understanding of the intervening Faraday screen arrangement along the line of sight.