Determination of the Ortho to Para Ratio of H2Cl+ and H2O+ from Submillimeter Observations

详细信息    查看全文

• 作者：Maryvonne Gerin ; Massimo de Luca ; Dariusz C. Lis ; Carsten Kramer ; Santiago Navarro ; David Neufeld ; Nick Indriolo ; Benjamin Godard ; Franck Le Petit ; Ruisheng Peng ; Thomas G. Phillips ; Evelyne Roueff
• 刊名：Journal of Physical Chemistry A
• 出版年：2013
• 出版时间：October 3, 2013
• 年：2013
• 卷：117
• 期：39
• 页码：10018-10026
• 全文大小：359K
• 年卷期：v.117,no.39(October 3, 2013)
• ISSN：1520-5215

文摘

The opening of the submillimeter sky with the Herschel Space Observatory has led to the detection of new interstellar molecular ions, H₂O⁺, H₂Cl⁺, and HCl⁺, which are important intermediates in the synthesis of water vapor and hydrogen chloride. In this paper, we report new observations of H₂O⁺ and H₂Cl⁺ performed with both Herschel and ground-based telescopes, to determine the abundances of their ortho and para forms separately and derive the ortho-to-para ratio. At the achieved signal-to-noise ratio, the observations are consistent with an ortho-to-para ratios of 3 for both H₂O⁺ and H₂Cl⁺, in all velocity components detected along the lines-of-sight to the massive star-forming regions W31C and W49N. We discuss the mechanisms that contribute to establishing the observed ortho-to-para ratio and point to the need for a better understanding of chemical reactions, which are important for establishing the H₂O⁺ and H₂Cl⁺ ortho-to-para ratios.