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arXiv · 1410.5945

A Substellar-Mass Protostar and its Outflow of IRAS 15398-3359 Revealed by Subarcsecond-Resolution Observations of H$_2$CO and CCH

Yoko Oya·Nami Sakai·Takeshi Sakai·Yoshimasa Watanabe·Tomoya Hirota·Johan E. Lindberg·Suzanne E. Bisschop·Jes K. Jørgensen·Ewine F. van Dishoeck·Satoshi Yamamoto
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Abstract

Sub-arcsecond ($0.^{\prime\prime}5$) images of H$_2$CO and CCH line emission have been obtained in the $0.8$ mm band toward the low-mass protostar IRAS 15398-3359 in the Lupus 1 cloud as one of the Cycle 0 projects of the Atacama Large Millimeter/Submillimeter Array. We have detected a compact component concentrated in the vicinity of the protostar and a well-collimated outflow cavity extending along the northeast-southwest axis. The inclination angle of the outflow is found to be about $20^\circ$, or almost edge-on, based on the kinematic structure of the outflow cavity. This is in contrast to previous suggestions of a more pole-on geometry. The centrally concentrated component is interpreted by use of a model of the infalling rotating envelope with the estimated inclination angle, and the mass of the protostar is estimated to be less than $0.09\ M_\odot$. Higher spatial resolution data are needed to infer the presence of a rotationally supported disk for this source, hinted at by a weak high-velocity H$_2$CO emission associated with the protostar.

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Yoko Oya, Nami Sakai, Takeshi Sakai, Yoshimasa Watanabe, Tomoya Hirota, Johan E. Lindberg, Suzanne E. Bisschop, Jes K. Jørgensen, Ewine F. van Dishoeck, Satoshi Yamamoto. 2014-10-22. A Substellar-Mass Protostar and its Outflow of IRAS 15398-3359 Revealed by Subarcsecond-Resolution Observations of H$_2$CO and CCH. https://doi.org/10.1088/0004-637x/795/2/152

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