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arXiv · 1707.03827

ALMA observations of dust polarization and molecular line emission from the Class 0 protostellar source Serpens SMM1

Charles L. H. Hull·Josep M. Girart·Łukasz Tychoniec·Ramprasad Rao·Paulo C. Cortés·Riwaj Pokhrel·Qizhou Zhang·Martin Houde·Michael M. Dunham·Lars E. Kristensen·Shih-Ping Lai·Zhi-Yun Li·Richard L. Plambeck
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Abstract

We present high angular resolution dust polarization and molecular line observations carried out with the Atacama Large Millimeter/submillimeter Array (ALMA) toward the Class 0 protostar Serpens SMM1. By complementing these observations with new polarization observations from the Submillimeter Array (SMA) and archival data from the Combined Array for Research in Millimeter-wave Astronomy (CARMA) and the James Clerk Maxwell Telescopes (JCMT), we can compare the magnetic field orientations at different spatial scales. We find major changes in the magnetic field orientation between large (~0.1 pc) scales -- where the magnetic field is oriented E-W, perpendicular to the major axis of the dusty filament where SMM1 is embedded -- and the intermediate and small scales probed by CARMA (~1000 AU resolution), the SMA (~350 AU resolution), and ALMA (~140 AU resolution). The ALMA maps reveal that the redshifted lobe of the bipolar outflow is shaping the magnetic field in SMM1 on the southeast side of the source; however, on the northwestern side and elsewhere in the source, low velocity shocks may be causing the observed chaotic magnetic field pattern. High-spatial-resolution continuum and spectral-line observations also reveal a tight (~130 AU) protobinary system in SMM1-b, the eastern component of which is launching an extremely high-velocity, one-sided jet visible in both CO(2-1) and SiO(5-4); however, that jet does not appear to be shaping the magnetic field. These observations show that with the sensitivity and resolution of ALMA, we can now begin to understand the role that feedback (e.g., from protostellar outflows) plays in shaping the magnetic field in very young, star-forming sources like SMM1.

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Charles L. H. Hull, Josep M. Girart, Łukasz Tychoniec, Ramprasad Rao, Paulo C. Cortés, Riwaj Pokhrel, Qizhou Zhang, Martin Houde, Michael M. Dunham, Lars E. Kristensen, Shih-Ping Lai, Zhi-Yun Li, Richard L. Plambeck. 2017-07-12. ALMA observations of dust polarization and molecular line emission from the Class 0 protostellar source Serpens SMM1. https://doi.org/10.3847/1538-4357%2Faa7fe9

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