标题： 星际气体中的氮化物：赫歇尔/赫菲观测 towards G10.6-0.4 (W31C) 显示英文标题

标题： Nitrogen hydrides in interstellar gas: Herschel/HIFI observations towards G10.6-0.4 (W31C)

摘要： 赫歇尔空间天文台上的HIFI仪器已被用于观测沿视线方向至G10.6-0.4的星际氮化物，以增进我们对氮的星际化学的理解。 我们报告了NH N=1-0, J=2-1和ortho-NH2 1_1,1-0_0,0的吸收观测。 我们还观测了ortho-NH3 1_0-0_0和2_0-1_0，para-NH3 2_1-1_1，并且未能成功探测到NH+。 所有检测都显示出与热核源本身直接相关的发射和吸收，以及在较宽的速度范围内由前景物质引起的吸收。 所有光谱显示类似的非饱和吸收特征，我们认为这是由于弥散分子气体。 估计了速度范围为11-54公里/秒内的总柱密度。 相似的谱线轮廓表明相对于氢的相对丰度相当均匀，分别为NH、NH2和NH3的大约6×10^-9、3×10^-9和3×10^-9。 这些丰度与气相和表面化学模型进行了讨论。 显示英文摘要

摘要： The HIFI instrument on board the Herschel Space Observatory has been used to observe interstellar nitrogen hydrides along the sight-line towards G10.6-0.4 in order to improve our understanding of the interstellar chemistry of nitrogen. We report observations of absorption in NH N=1-0, J=2-1 and ortho-NH2 1_1,1-0_0,0. We also observed ortho-NH3 1_0-0_0, and 2_0-1_0, para-NH3 2_1-1_1, and searched unsuccessfully for NH+. All detections show emission and absorption associated directly with the hot-core source itself as well as absorption by foreground material over a wide range of velocities. All spectra show similar, non-saturated, absorption features, which we attribute to diffuse molecular gas. Total column densities over the velocity range 11-54 km/s are estimated. The similar profiles suggest fairly uniform abundances relative to hydrogen, approximately 6*10^-9, 3*10^-9, and 3*10^-9 for NH, NH2, and NH3, respectively. These abundances are discussed with reference to models of gas-phase and surface chemistry.