日本地球惑星科学連合2015年大会

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セッション記号 P (宇宙惑星科学) » P-PS 惑星科学

[P-PS24] 宇宙における物質の形成と進化

2015年5月27日(水) 14:15 〜 16:00 A02 (アパホテル&リゾート 東京ベイ幕張)

コンビーナ:*橘 省吾(北海道大学大学院理学研究院自然史科学専攻地球惑星システム科学分野)、三浦 均(名古屋市立大学大学院システム自然科学研究科)、大坪 貴文(東京大学大学院総合文化研究科)、本田 充彦(神奈川大学理学部数理物理学科)、座長:大坪 貴文(東京大学大学院総合文化研究科)

14:30 〜 14:45

[PPS24-09] 量子化学計算による星間ダストでのグリシン生成の研究

*木立 佳里1梅村 雅之1庄司 光男1小松 勇1栢沼 愛1重田 育照1 (1.筑波大学)

Amino acids in the primitive earth may have been originated in the interstellar medium (ISM). Many amino acids and their precursors were found in the meteorites and were detected in laboratory experiments of UV irradiation on interstellar ice analogs. Moreover, various organic molecules were detected in molecular clouds; recently the detection of amino acid has been expected, especially by ALMA
In this study, we would like to make clear the mechanism of the simplest amino acid, glycine formation in the ISM using accurate quantum chemical calculation (density functional theory; DFT). Glycine formation pathway via hydantoin, which is glycine precursor detected in Murchison meteorite, were investigated. At first, the reactions in the gas-phase were examined. As a result, it was unlikely that glycine was formed during the lifetime of molecular clouds. However, there is a possibility that the reactions proceed with catalysis or the outside energies such as UV and heat.
Organic molecules in the ISM are considered to be generated on icy interstellar dust grains. In a previous study, the reaction barriers in aminoacetonitrille precursor formation pathway become lower with water molecules than those in the gas-phase, since water molecules on the ice core can play crucially a proton-transfer role, facilitating the basic transformations in the glycine formation pathways, [1]. We investigate the hydantoin and glycine formation pathway with one water molecule as a simplest model of ice.

[1] D. M. Koch, et.al. J. Phys. Chem. C112, 2972 (2008)