光深对大质量恒星形成团块化学性质研究的影响

本文使用文献中的N₂H⁺(1-0)、H¹³CO⁺(1-0)、HCN(1-0)和HN¹³C(1-0)谱线数据研究大质量恒星形成团块的化学性质和演化，发现H¹³CO⁺和HN¹³C的丰度受H₂柱密度的影响. 由于从A阶段到B阶段这两个丰度的中值增加了近10倍，H¹³CO⁺和HN¹³C适合追踪大质量恒星形成团块的演化. 从A到B阶段四种分子丰度增长速度从高到低依次为H¹³CO⁺、HCN、HN¹³C、N₂H⁺. 结果表明进行光学薄分子谱线的高分辨率观测对于研究大质量恒星形成团块的化学演化是必要的.

Effect of Optical Depth on Study of Chemical Properties of Massive Star Forming Clumps

Here we present the study on chemical properties of massive star forming clumps using N₂H⁺(1-0), H¹³CO⁺(1-0), HCN(1-0) and HN¹³C(1-0)) data from the literature Astron. As-trophys. 563, A97 (2014)]. We found that abundances of H¹³CO⁺ and HN¹³C are a ected by H₂ column densities. As the median values of these two abundances increase by nearly 10 times from stages A to B, H¹³CO⁺ and HN¹³C are suitable for tracing the evolution of massive star forming clumps. The order of rapidity in growth of abundances of all the four studied molecules from stages A to B, is H¹³CO⁺, HCN, HN¹³C, and N₂H⁺, from the highest to the lowest. Our results suggest that the observing optically thin molecular lines with high angular resolution are necessary to study the chemical evolution of massive star forming clumps.