在猎户座KL方向探测到OH$^+$和H$_2$O$^+$
星系天体物理
2015-05-19 v1
摘要
我们报告了利用赫歇尔空间天文台/HIFI在猎户座KL方向对反应性分子离子OH、HO和HO的观测结果。OH在909、971和1033 GHz处的所有三条精细结构跃迁，以及{\it ortho}-HO 跃迁在1115和1139 GHz处的双线两个精细结构分量均被探测到；获得了HO的上限。OH和HO纯粹以吸收线形式被观测到，显示出一个位于源速度9 km s的窄分量，以及一个宽的蓝移吸收，类似于最近报道的HF和{\it para}-HO，并归因于猎户座KL的低速外流。我们估计了9 km s分量中OH和HO的柱密度分别为cm和cm，外流中的柱密度分别为cm和cm。从985和1657 GHz附近的跃迁推导出{\it ortho}和{\it para}-HO柱密度的上限分别为cm和cm。这三种离子的柱密度比最近对W31C和W49N的观测结果低一个数量级。相对较低的柱密度可能由更高的气体密度解释，尽管假设了非常高的电离率。
引用
@article{arxiv.1009.1450,
title = {Detection of OH$^+$ and H$_2$O$^+$ towards Orion~KL},
author = {H. Gupta and P. Rimmer and J. C. Pearson and S. Yu and E. Herbst and N. Harada and E. A. Bergin and D. A. Neufeld and G. J. Melnick and R. Bachiller and W. Baechtold and T. A. Bell and G. A. Blake and E. Caux and C. Ceccarelli and J. Cernicharo and G. Chattopadhyay and C. Comito and S. Cabrit and N. R. Crockett and F. Daniel and E. Falgarone and M. C. Diez-Gonzalez and M. -L. Dubernet and N. Erickson and M. Emprechtinger and P. Encrenaz and M. Gerin and J. J. Gill and T. F. Giesen and J. R. Goicoechea and P. F. Goldsmith and C. Joblin and D. Johnstone and W. D. Langer and B. Larsson and W. B. Latter and R. H. Lin and D. C. Lis and R. Liseau and S. D. Lord and F. W. Maiwald and S. Maret and P. G. Martin and J. Martin-Pintado and K. M. Menten and P. Morris and H. S. P. Müller and J. A. Murphy and L. H. Nordh and M. Olberg and V. Ossenkopf and L. Pagani and M. Pérault and T. G. Phillips and R. Plume and S. -L. Qin and M. Salez and L. A. Samoska and P. Schilke and E. Schlecht and S. Schlemmer and R. Szczerba and J. Stutzki and N. Trappe and F. F. S. van der Tak and C. Vastel and S. Wang and H. W. Yorke and J. Zmuidzinas and A. Boogert and R. Güsten and P. Hartogh and N. Honingh and A. Karpov and J. Kooi and J. -M. Krieg and R. Schieder and P. Zaal},
journal= {arXiv preprint arXiv:1009.1450},
year = {2015}
}
备注
5 pages, 1 figure. Accepted to and to be published in the Herschel HIFI special issue of A\&A Letters