Magnetic field configuration at the central region of our Galaxy

It has been long debated whether the magnetic field configuration at the central region of our Galaxy is toroidal or poloidal. Previous works that have addressed this question were mainly based on radio observations of non-thermal radio filaments, and sub-mm polarimetric observations of dense molecular clouds. I will present a result of a wide-field near-infrared polarimetric survey of the central 2 deg by 2deg region; these wavelengths trace polarization of starlight due to extinction by magnetically-aligned interstellar dust grains. We have found a transition of a large-scale magnetic field configuration. Near the Galactic plane, the magnetic field is almost parallel to the Galactic plane; however, at high Galactic latitudes (|b|>0.4), the field is nearly perpendicular to the plane. This configuration has important implications for understanding the origin of the magnetic field in this region.


01/07/2010 - 14:00
Shogo Nishiyama
Kyoto University, Japan