[P-PS09] 宇宙における物質の形成と進化

[PPS09-06] 星・惑星系形成領域における水素・窒素同位体分別

★招待講演

*古家 健次¹ (1.筑波大学　計算科学研究センター)

キーワード：同位体分別、星・惑星系形成領域

Molecular isotope ratios are useful tools to investigate the molecular evolution in star- and planet-forming regions. Radio observations have revealed that molecules in star- and planet-forming regions are significantly enriched in deuterium. This can be, at least qualitatively, explained by low temperature (< several tens K) gas phase chemistry, which prefer transferring deuterium from HD (i.e., the main form of deuterium) to other molecules. On the other hand, it has been found that molecules in the cold gas of star-forming regions are not necessarily enriched in heavy nitrogen (15N), rather they tend to be depleted in 15N. The mechanism of 15N fractionation in star-forming regions remains unclear. In this presentation, we discuss recent observational and theoretical findings on hydrogen and nitrogen fractionation in star- and planet forming regions.