Revealing chemical reactions in high-mass star-forming regions with observations, laboratory experiments, and chemical network simulations

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K14523
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 16010:Astronomy-related
• Research Institution: National Astronomical Observatory of Japan (2021-2023); Gakushuin University (2020)
• Principal Investigator: TANIGUCHI Kotomi 国立天文台, 科学研究部, 特任助教 (40865549)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 星間化学 / 電波天文学 / 星形成

Outline of Final Research Achievements

I have studies formation and destruction mechanisms of carbon-chain molecules around massive young stellar objects by observations using ALMA and chemical network simulations. Cyanodiacetylene (HC5N), one of the carbon-chain species, has been detected from three massive young stellar objects among five target sources. I have confirmed that HC5N emission comes from hot regions with temperatures above 100 K combining with the chemical network simulations. The formation process of carbon-chain species around massive stars is different from that around low-mass protostars, Warm Carbon-Chain Chemistry (WCCC). I have proposed Hot Carbon-Chain Chemistry to explain the observed abundances of HC5N around massive stars, and shown chemical diversity around massive young stellar objects.

Free Research Field

天文学

Academic Significance and Societal Importance of the Research Achievements

原始星周囲の炭素鎖分子の生成・破壊メカニズムや化学的多様性については、太陽系近傍の低質量星形成領域のみで進められてきた。本研究で、大質量星原始星周囲での独自の炭素鎖分子の生成メカニズムの発見と化学的多様性の発見は世界でも初めての成果である。また、大質量星形成領域での研究が進んだことで、幅広い温度や密度などの物理パラメータと化学組成の比較が可能になり、原始星周囲の物理と化学の関係について研究が進められるようになった。