SF-11-0004

Dust Polarization Study of Prestellar and Protostellar Sources in Orion Molecular Cloud 3 region

Yuhua Liu, Satoko Takahashi, Masahiro Machida, Paul Ho, Josep Miquel Girart, Kouichiro Nakanishi, Kohji Tomisaka, Asako Sato

We present 1.1 mm Atacama Large Millimeter/submillimeter Array (ALMA) dust linear polarization observations at ~0.1” (~40au) toward one prestellar, four Class 0, one Class I, and one flat spectrum sources embedded within the Orion Molecular Cloud-3 (OMC-3) region (d=400 pc). We detected polarized emission toward four protostellar sources, while no polarized emission was detected toward one prestellar and two Class 0 sources because these three sources are the youngest and weakest among all the other sources observed here, the 3σ upper limit of the polarization fraction for the non-detection sources are between 0.5% and 4%. Two Class 0, one Class I, and one flat spectrum sources detected in the polarized emission show compact disk-like structures with a size ranging between 32 au and 100 au. Organized polarization E-vectors aligned with their minor axes are detected. Measured mean polarization fraction values for the three sources are between 0.3% and 0.8%. One of the Class 0 sources showed a very high mean polarization fractions of 2.8% at the center and 8.8% on a streamer. Origins of the polarized emission detected in these sources could be explained by either the dust alignment with magnetic fields, self-scattering, and dust alignment due to radiative torques. We present observational results from individual sources, discuss origin of their polarized emission, and finally make comparisons among all the samples at different evolutionary stages to see how polarization characteristics change with their evolutionary stages.