Physical Structure and Chemical Evolution during the Disk-Formation Process Traced by Sulfur-Bearing Species

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K14753
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 16010:Astronomy-related
• Research Institution: The University of Tokyo
• Principal Investigator: Oya Yoko 東京大学, 大学院理学系研究科(理学部), 助教 (00813908)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: 電波天文学 / 星形成 / 星間物質

Outline of Final Research Achievements

This project aimed to understand the chemical evolution in planet-forming regions of Solar-type protostars by delineating the physical structures and chemical distributions in their disk-forming regions, including their mutual relation. To achieve this goal, we performed high sensitivity and high spatial-resolution radio observations, especially focusing on the sulfur-bearing species.
We delineated the complex physical structures in the vicinity of Solar-type protostellar sources with the molecular lines of various sulfur-bearing species. We found that the physical structure drastically changes from the envelope to the disk. Moreover, the sulfur-bearing species show chemical differentiation along with the change in the physical structure. We also found the diversity in the chemical compositions of sulfur-bearing species among Solar-type protostars. We suggested that this diversity can be originated from the initial gas and dust temperatures before the birth of protostars.

Free Research Field

天文学

Academic Significance and Societal Importance of the Research Achievements

若い太陽型原始星まわりでの惑星系形成と、そこでの物質進化を探ることは、我々が住む地球のもつ豊かな環境の起源の理解に直結する重要な研究課題である。しかし、惑星系の母体である原始惑星系円盤が、原始星の周りに「いつ」「どのようにして」作られるのか、またそこでどのような物質進化が起きているのかについては、観測的にも理論的にも未開拓の領域として残されてきた。本研究課題では、太陽系内の彗星でも検出され注目を集める硫黄関連分子を軸に、惑星系形成領域における物理過程と物質進化の理解を前進させた。この成果は、惑星系形成領域と太陽系化学を結びつける端緒を与えると期待される。