Magnetic substructure in the northern Fermi Bubble revealed by polarized WMAP emission

TL;DR

This paper uncovers a magnetic substructure in the northern Fermi Bubble through polarized microwave emission, revealing connections to gamma-ray features and Galactic center structures, suggesting a common origin.

Contribution

It identifies a magnetic substructure in the northern Fermi Bubble and links microwave polarization features to gamma-ray and radio structures, indicating a shared Galactic center origin.

Findings

Polarized microwave structures align with gamma-ray features.

Magnetic field data suggest non-local origin of the structures.

Evidence supports a connection between the Galactic center spur and the Fermi Bubble.

Abstract

We report a correspondence between giant, polarized microwave structures emerging north from the Galactic plane near the Galactic center and a number of GeV gamma-ray features, including the eastern edge of the recently-discovered northern Fermi Bubble. The polarized microwave features also correspond to structures seen in the all-sky 408 MHz total intensity data, including the Galactic center spur. The magnetic field structure revealed by the polarization data at 23 GHz suggests that neither the emission coincident with the Bubble edge nor the Galactic center spur are likely to be features of the local ISM. On the basis of the observed morphological correspondences, similar inferred spectra, and the similar energetics of all sources, we suggest a direct connection between the Galactic center spur and the northern Fermi Bubble.