The Spiral Magnetic Field in the Central 5 Parsecs of the Galaxy

At λ ≈ 50 microns, the most prominent feature in the inner parsecs of the Milky Way is the rotating, irregular Circum-Nuclear Ring (CNR) which demarcates the inner boundary of the molecular gas that is likely spiraling in toward the supermassive black hole. The gas is magnetized, with previous estimates of field strength exceeding 1 milliGauss. We present new observations of the polarization and inferred magnetic field structure of the CNR and vicinity, made at λ = 53 microns with the HAWC+ instrument on SOFIA. These observations show a spiral magnetic field on scales of 0.5 - 5 pc, with organized components, but mostly lacking the 180 degree symmetry of existing magnetized accretion disk models. We discuss estimates of the magnetic field strength from the 53 micron data, the relationship of these data to observations at shorter and longer far-infrared wavelengths, and interpretation of several of the magnetic features observed.