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| EPoS Contribution |
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Protostellar Outflows in the Perseus Molecular Clouds
Yichen Zhang RIKEN, Wako-Shi, JP | |
| Unbiased survey of protostellar outflows are necessary to understand the launch of outflow from disk and the development of outflow through evolution. I will present the initial results of the ALMA Band 6 chemical survey towards the protostellar sources in the Perseus Molecular Cloud. The targets are selected to be Class 0 and I sources with bolometric luminosities >1 Lsun and envelope masses >1 Msun. The survey reveals rich outflow phenomena, traced by various molecules, including SiO, CS and CCH. Among the 37 sources we have analyzed so far, we are able to identify 21 outflows, which can be roughly categorized into four types based on their chemical and morphological characteristics: 1) highly collimated SiO jets surrounded by narrow CS and/or CCH outflows; 2) highly collimated SiO jets and significantly wider CS/CCH outflows; 3) extended outflows without SiO jet; 4) base of outflow cavities outlined by CS and/or CCH. We found that the opening angle of the outflow increases with the evolution of the protostar indicated by the bolometric temperature or the luminosity to envelope mass ratio. We also found that the four categories identified above generally follow the evolutionary sequences, with the SiO outflow only seen in the earliest stage, while the later stage outflows only seen in CCH or CS. I will also show that in two sources, CS and/or CCH emission reveals outflow shells rotating in a way that conserves angular momentum. Such structures connect to the central rotating envelope/disk system, which further provides clues for understanding the launch of outflows. | |
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| Caption: The outflow opening angles vs. the bolometric temperature of the sources. The colors of the data points corresponds to the four types of sources: Red: collimated SiO jets surrounded by narrow CS and/or CCH outflows; Magenta: collimated SiO jets and significantly wider CS/CCH outflows; Black: extended outflows without SiO jet; Blue: base of outflow cavities outlined by CS and/or CCH. | |
| Collaborators: A. Higuchi, RIKEN, JP N. Sakai, RIKEN, JP A. Lopez-Sepulcre, IRAM, FR Y. Oya, U Tokyo, JP M. Imai, U Tokyo, JP Y. Watanabe, U Tsukuba, JP B. Lefloch, IPAG, FR C. Ceccarelli, IPAG, FR S. Yamamoto, U Tokyo, JP |
Suggested Session:
Galactic-scale star formation |