Magnetic field morphologies at mpc scale

Abstract

We report our new results of the magnetic field (B) morphologies toward W51 North, traced with the linear polarization of the dust continuum at wavelengths of 870 μm. The B morphologies are resolved with an angular resolution of typically 1” using the Submillimeter Array (SMA). Dense structures with a number density 105 to 107 cm−3 are traced. In comparison, the B morphologies of sources at different evolutionary stages, from the collapsing core in W51 e2 (Tang et al. 2009a) and part of Orion BN/KL (Tang et al. 2010) to the ultra-compact HII region G5.89-0.39 (Tang et al. 2009b) clearly exhibit different morphologies, likely suggesting different roles of the B fields at different stages.