在暗星云L134N中检测一氧化氮。

Detection of nitric oxide in the dark cloud L134N.

作者信息

McGonagle D, Ziurys L M, Irvine W M, Minh Y C

机构信息

Department of Physics and Astronomy, University of Massachusetts, Amherst, USA.

出版信息

Astrophys J. 1990 Aug 10;359(1 Pt 1):121-4. doi: 10.1086/169040.

DOI:10.1086/169040

PMID:11538685

Abstract

We report the first detection of interstellar nitric oxide (NO) in a cold dark cloud, L134N. Nitric oxide was observed by means of its two 2 pi 1/2, J = 3/2 --> 1/2, rotational transitions at 150.2 and 150.5 GHz, which occur because of lambda-doubling. The inferred column density for L134N is N(NO) approximately 5 x 10(14) cm-2 toward the SO peak in that cloud. This value corresponds to a fractional abundance relative to molecular hydrogen of f(NO) approximately 6 x 10(-8) and is in good agreement with predictions of quiescent cloud ion-molecule chemistry. NO was not detected toward the dark cloud TMC-1 at an upper limit of f(NO) < or = 3 x 10(-8).

摘要

我们报告了在冷暗云L134N中首次探测到星际一氧化氮（NO）。通过其在150.2和150.5千兆赫的两个2π1/2、J = 3/2→1/2的转动跃迁观测到一氧化氮，这是由λ双重分裂产生的。朝向该云团中SO峰值方向，L134N的推断柱密度为N(NO)约5×10¹⁴厘米⁻²。该值对应相对于分子氢的分数丰度f(NO)约6×10⁻⁸，与静态云离子 - 分子化学的预测结果吻合良好。在暗云TMC - 1中未探测到NO，其上限为f(NO)≤3×10⁻⁸。