Charting the Interstellar Magnetic Field behind the Interstellar Boundary Explorer (IBEX) Ribbon
Monday, 15 December 2014: 5:30 PM
Magnetic fields are a key component of the interstellar medium. Starlight polarized by aligned charged interstellar dust grains provided the first evidence of a magnetic field in the solar galactic environment. The IBEX Ribbon of energetic neutral atoms traces the interstellar magnetic field draping over the heliosphere. Magnetic fields thread nearby interstellar clouds, which include both partially-ionized low-density gas, as well as dense gas. Rudimentary maps of the interstellar magnetic field direction in the solar vicinity, based on polarized starlight, show that multiple field directions are found locally. The dominant local magnetic structure has a direction matching that of the magnetic field traced by the IBEX Ribbon. This magnetic structure, and the kinematics of nearby interstellar gas, suggest that the Loop I superbubble extends to the solar vicinity. A separate magnetic filament with intriguing properties has been identified. The structure of the magnetic field within 40 pc is related to the distribution and kinematics of local clouds that are observed through the absorption lines they form in stellar spectra.