천문학회보 (The Bulletin of The Korean Astronomical Society)
- 제45권1호
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- Pages.57.2-57.2
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- 2020
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- 1226-2692(pISSN)
Two distinct types of dust polarization in the disk and its vicinity around the protostar TMC-1A
- Aso, Yusuke (KASI) ;
- Kwon, Woojin (SNU) ;
- Ching, Tao-Chung (NAOC) ;
- Lai, Shih-Ping (National Tsing Hua University) ;
- Li, Zhi-Yun (The University of Virginia) ;
- Hirano, Naomi (ASIAA) ;
- Rao, Ramprasad (Harvard-Smithsonian CfA)
- 발행 : 2020.10.13
초록
We observed the Class I protostar TMC-1A in polarized dust emission at 1.3 mm at a spatial resolution of ~40 au using ALMA. Previous observations revealed a disk (r~100 au), surrounded by an infalling envelope, and a CO outflow going in the north-south direction in TMC-1A. Our observations detected polarized dust emission in a central region (r~50 au) and ~100 au north and south of the central protostar. The former polarization is likely due to self-scattering because of the polarization direction along the disk minor axis, the polarization fraction independent of Stokes I, and a high optical thickness. The latter polarization is roughly in the outflow region. The position and direction, particularly in the north, imply multiple possible mechanisms: magnetically or mechanically aligned dust grains in the outflow or in an accretion flow.
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