Poster Presentation
Envelope Structure of Isolated Protostellar Source CB244
Presenter: Muneaki Imai (The University of Tokyo)
An isolated protostellar core without influences of nearby stars/protostars provides us with an ideal testbed of star formation theories. In this context, exploring the chemical and physical structures of an isolated source is of fundamental importance.
We report chemical and physical structures of the envelope of the low-mass protostar in the Bok globule CB244 observed with NOEMA. This source is found to be deficient in molecular lines, and only 11 lines of molecular species are detected. No saturated complex organic molecule (COM) except for CH3OH is detected, while carbon-chain molecules are detected in the envelope. Thus, warm carbon-chain chemistry (WCCC) is seen in this source, while hot corino chemistry is not confirmed. The chemical characteristics of CB244 seem different from that of another isolated source B335, showing both WCCC and hot corino chemistry. This result suggests that the chemical properties are different even among the isolated sources.
In CB244, the main tracers of the envelope are CS, SO, and H13CO+. Although their distributions are different from each other, concatenation of their kinematic structure enables us to provide the structure of the infalling and rotating envelope. The protostellar mass and the radius of the centrifugal barrier are estimated to be 0.4 Msun and <300 au by the infalling and rotating envelope model.
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