Binary formation in Lupus Molecular Clouds with high resolution NIR and Radio observations

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K05303
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Astronomy
• Research Institution: National Astronomical Observatory of Japan
• Principal Investigator: Saito Masao 国立天文台, TMT推進室, 教授 (90353424)
• Co-Investigator(Kenkyū-buntansha): 西合 一矢 国立天文台, アルマプロジェクト, 特任助教 (30399290)
• Research Collaborator: Itziar de Gregorio-Monsalvo ; Adele Plunkett ; Koraljka Muzic ; Rebekka Grellmann ; Takahashi Satoko ; Antonio Hales ; Christian Lopez ; Lewis Knee
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 電波天文学 / 星形成 / 連星

Outline of Final Research Achievements

We carried out an unbiased study with ALMA to investigate the binary properties at the early phase in Lupus molecular clouds and binary formation, a major mode of star formation in most nearby star forming regions. Surprisingly, our results indicate that the binary population in the early stages is very low and only one protobinary candidate was identified. It could be due to specific environment of this star forming region. Further, we found an intersting object that shows extended emission in continuum and the emission distribution appears to show two arms or spiral structure. We also detected molecular line emission toward this source having a velocity gradient roughly along the major axis of the continuum disk presumably suggestive of a rotating disk. Its kinematics is not simple Keplerian and infall or outflowing motion is suggested, which may explain the spiral structure.

Free Research Field

電波天文学

Academic Significance and Societal Importance of the Research Achievements

私たちの太陽は現在単独星であるが、近傍の星を調べると多くの星は連星となっている。そこで、単独星と連星を決めるメカニズムを知ることは宇宙における単独星の誕生およびその周囲の惑星形成の理解につながる。生命の発生進化は多くの場合単独星で起こると考えられるので、本研究は宇宙における生命を育む惑星がどのようにできたかという理解へつながるものと考える。