- The D/H Ratio of Water Ice at Low Temperatures
- The D/H Ratio of Water Ice at Low Temperatures
- ㆍ 저자명
- 이정은,Lee. Jeong-Eun,Bergin. Edwin
- ㆍ 간행물명
- 천문학회보
- ㆍ 권/호정보
- 2011년|36권 2호|pp.105-105 (1 pages)
- ㆍ 발행정보
- 한국천문학회
- ㆍ 파일정보
- 정기간행물|ENG| PDF텍스트
- ㆍ 주제분야
- 기타
We present the modeling results of deuterium fractionation of water ice, $H_2$, and the primary deuterium isotopologues of $H3^+$ in the physical conditions associated with the star and planet formation process. We calculated the deuterium chemistry for a range of gas temperatures (Tgas~10-30 K) and ortho/para ratio (opr ) of $H_2$ based on state-to-state reaction rates and explore the resulting fractionation including the formation of a water ice mantle coating grain surfaces. We find that the deuterium fractionation exhibits the expected temperature dependence of large enrichments at low gas temperature, but only for opr-H2<0.01. More significantly the inclusion of water ice formation leads to large D/H ratios in water ice (${geq}10^{-2}$ at 10 K) but also alters the overall deuterium chemistry. For T<20 K the implantation of deuterium into ices lowers the overall abundance of HD which reduces the efficiency of deuterium fractionation at high density. Under these conditions HD will not be the primary deuterium reservoir in the cold dense interstellar medium and $H3^+$ will be the main charge carrier in the dense centers of pre-stellar cores and the protoplanetary disk midplane.