Protostellar Jet and Outflow in the Collapsing Cloud Core

Masahiro N. Machida, Shu ichiro Inutsuka, Tomoaki Matsumoto

研究成果: 書籍/レポート タイプへの寄稿会議への寄与

3 被引用数 (Scopus)

抄録

Using three-dimensional resistive MHD nested grid simulations, we investigate the driving mechanism of outflows and jets in star formation process. Starting with a Bonnor-Ebert isothermal cloud rotating in a uniform magnetic field, we calculated cloud evolution from the molecular cloud core (nc = 104 cm − 3, r = 4. 6 ×104 AU) to the stellar core (nc = 1022 cm − 3, r ∼ 1R), where nc and r denote the central density and radius of each object, respectively. In the collapsing cloud core, we found two distinct flows: Low-velocity outflows (∼ 5 km) with a wide opening angle, driven from the adiabatic core, and high-velocity jets (∼ 30 km) with good collimation, driven from the protostar. High-velocity jets are enclosed by low-velocity outflow. The difference in the degree of collimation between the two flows is caused by the strength of the magnetic field and configuration of the magnetic field lines. The magnetic field around an adiabatic core is strong and has an hourglass configuration; therefore, the low-velocity outflow from the adiabatic core are driven mainly by the magnetocentrifugal mechanism and guided by the hourglass-like field lines. In contrast, the magnetic field around the protostar is weak and has a straight configuration owing to Ohmic dissipation in the high-density gas region. Therefore, high-velocity jet from the protostar are driven mainly by the magnetic pressure gradient force and guided by straight field lines. Differing depth of the gravitational potential between the adiabatic core and the protostar cause the difference of the flow speed. Low-velocity outflows correspond to the observed molecular outflows, while high-velocity jets correspond to the observed optical jets. We suggest that the protostellar outflow and the jet are driven by different cores, rather than that the outflow being entrained by the jet.

本文言語英語
ホスト出版物のタイトルProtostellar Jets in Context
編集者Kanaris Tsinganos, Tom Ray, Matthias Stute
出版社Springer Science and Business Media B.V.
ページ405-410
ページ数6
ISBN(印刷版)9783642005756
DOI
出版ステータス出版済み - 2009
外部発表はい
イベントConference on Protostellar Jets in Context, 2008 - Island of Rhodes, ギリシャ
継続期間: 7月 7 20087月 12 2008

出版物シリーズ

名前Astrophysics and Space Science Proceedings
ISSN(印刷版)1570-6591
ISSN(電子版)1570-6605

会議

会議Conference on Protostellar Jets in Context, 2008
国/地域ギリシャ
CityIsland of Rhodes
Period7/7/087/12/08

!!!All Science Journal Classification (ASJC) codes

  • 物理学および天文学一般
  • コンピュータ サイエンスの応用
  • 分光学
  • 宇宙惑星科学
  • 核物理学および高エネルギー物理学

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