Magnetic Fields in Star-forming Molecular Clouds. II. The Depolarization Effect in the OMC-3 Filament of Orion A

Polarized 850 μm thermal emission data of the region OMC-3 in the Orion A molecular cloud are presented. These data, taken in 1998 with the SCUBA polarimeter mounted on the James Clerk Maxwell Telescope, have been rereduced using improved software. The polarization pattern is not suggestive of a uniform field structure local to OMC-3, nor does the orientation of the vectors align with existing polarimetry maps of the OMC-1 core 20' to the …