Formation of ices and organic molecules in interstellar molecular clouds

2017 Fiscal Year Final Research Report

• Project Area: Evolution of molecules in space: from interstellar clouds to proto-planetary nebulae
• Project/Area Number: 25108002
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Science and Engineering
• Research Institution: Hokkaido University
• Principal Investigator: KOUCHI Akira 北海道大学, 低温科学研究所, 教授 (60161866)
• Co-Investigator(Kenkyū-buntansha): 羽馬 哲也 北海道大学, 低温科学研究所, 助教 (20579172) ; 日高 宏 北海道大学, 低温科学研究所, 助教 (00400010) ; 橘 省吾 東京大学, 理学系研究科, 教授 (50361564) ; 薮下 彰啓 九州大学, 総合理工学研究院, 准教授 (70371151) ; 荒木 光典 東京理科大学, 総合研究機構, プロジェクト研究員 (90453604) ; 中野 英之 京都教育大学, 教育学部, 准教授 (80554310)
• Co-Investigator(Renkei-kenkyūsha): KAWANO Jun 北海道大学, 理学研究院, 准教授 (40378550)
• Project Period (FY): 2013-06-28 – 2018-03-31
• Keywords: 星間分子雲 / 表面原子反応 / 光化学反応 / 氷 / 有機物

Outline of Final Research Achievements

To understand the formation and evolution mechanism of molecules in interstellar molecular clouds, we have performed experiments on surface atomic reactions and photochemical reactions. In surface atomic reaction experiments, we have clarified formation and H/D fractionation mechanism of important molecules and succeeded to draw general description of quantum tunneling reactions. Furthermore, we observed surface structure of amorphous ice by atomic force microscope and showed that water molecule formed at 10 K shows a statistical high-temperature ortho/para ratio of 3, invalidating the assumed relation between ortho/para ratio and temperature. In photochemical reaction experiments, we observed organic refractory residue by some microscopes and found singular texture which was found in interplanetary dusts and some primitive meteorites. We also found that UV-irradiated amorphous ices behave like liquid at temperatures between 50 and 150 K.

Free Research Field

地球惑星科学，天文学