标题： CHD$_{2}$OH在预恒星核中的首次检测 显示英文标题

标题： First detection of CHD$_{2}$OH towards pre-stellar cores

摘要： 通过氘化作用追踪了物质在恒星和行星形成过程中的继承关系。 我们在此报告首次在预恒星核中检测到双氘化甲醇。 我们研究了甲醇，CH$_{3}$OH，在两个无恒星核和两个预恒星核中的氘化作用。 我们得出预恒星核H-MM1和L694-2中CH$_{2}$DOH的D/H比率为0.8-1.9$\%$，这与更演化的Class 0/I天体和彗星67P/丘留莫夫-格拉西缅科的测量结果一致，表明在预恒星阶段出现了直接的化学联系。 此外，CHD$_{2}$OH/CH$_{2}$DOH 的柱密度比为$\sim$50-80$\%$，与面向 Class 0/I 天体的比值一致，表明 CHD$_{2}$OH 的形成机制效率很高，可能通过 H 原子对 D$_{2}$CO 的加成实现。 CH$_{2}$DOH/CH$_{3}$OH 和 CHD$_{2}$OH/CH$_{3}$OH 的柱密度比在两个预恒星核中大于在两个无恒星核 B68 和 L1521E 中的比值，代表了早期阶段核中甲醇氘化的演化趋势。 显示英文摘要

摘要： The inheritance of material across the star and planet formation process is traced by deuterium fractionation. We report here the first detection of doubly deuterated methanol towards pre-stellar cores. We study the deuterium fractionation of methanol, CH$_{3}$OH, towards two starless and two pre-stellar cores. We derive a D/H ratio of 0.8-1.9$\%$ with CH$_{2}$DOH in pre-stellar cores H-MM1 and L694-2, consistent with measurements in more evolved Class 0/I objects and comet 67P/Churyumov-Gerasimenko, suggesting a direct chemical link arising in the pre-stellar stage. Furthermore, the column density ratios of CHD$_{2}$OH/CH$_{2}$DOH are $\sim$50-80$\%$, consistently high as that towards Class 0/I objects, indicating an efficient formation mechanism of CHD$_{2}$OH, possibly through H atom additions to D$_{2}$CO. The CH$_{2}$DOH/CH$_{3}$OH and CHD$_{2}$OH/CH$_{3}$OH column density ratios in the two pre-stellar cores are larger than that in the two starless cores B68 and L1521E, representing an evolutionary trend of methanol deuteration in early-stage cores.