arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1306.1681astro-ph.GAphysics.chem-ph
收藏

星际空间中氰基甲醛的形成

Formation of Cyanoformaldehyde in the interstellar space

Ankan Das, Liton Majumdar, Sandip K. Chakrabarti, Rajdeep Saha, Sonali Chakrabarti

备注：
20 pages, 7 figures
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

最近，绿岸望远镜怀疑人马座B2（N）中有氰甲醛（HCOCN）分子，尽管这一观测结果尚未得到证实。在恒星形成区及其周围，这种分子可以通过两种丰富的星际物质H2CO和CN之间的放热反应形成。迄今为止，该分子形成的反应速率系数是未知的。有根据的猜测被用来通过化学建模来解释这种分子的丰度。本文通过量子化学计算，得到了HCOCN生成的经验速率系数以及HCOCN分子生成过程中不同的化学性质。虽然HCOCN对单分子分解是稳定的，但这种气相分子可以通过许多其他方式被破坏，例如：离子分子反应或宇宙射线的作用。离子-分子反应速率是用俘获理论计算的。我们还将获得的速率系数纳入我们的大型气体-颗粒化学网络，以研究这些物种在各种星际条件下的化学演化。还研究了HCOCN的同位素体之一（DCOCN）的形成。我们的研究预测了在冰相中发现具有相当高丰度的HCOCN和DCOCN的可能性。为了在各种星际环境中探测HCOCN或DCOCN，有必要了解这些分子的光谱特性。为此，我们进行了量子化学计算，以找出不同的光谱参数的HCOCN的电子，红外和转动模式的转变。我们清楚地表明同位素取代（DCOCN）在HCOCN的振动级数中起着重要作用。

英文摘要：

Cyanoformaldehyde (HCOCN) molecule has recently been suspected towards the Sagittarius B2(N) by the Green Bank telescope, though a confirmation of this observation has not yet been made. In and around a star forming region, this molecule could be formed by the exothermic reaction between two abundant interstellar species, H2CO and CN. Till date, the reaction rate coefficient for the formation of this molecule is unknown. Educated guesses were used to explain the abundance of this molecule by chemical modeling. In this paper, we carried out quantum chemical calculations to find out empirical rate coefficients for the formation of HCOCN and different chemical properties during the formation of HCOCN molecules. Though HCOCN is stable against unimolecular decomposition, this gas phase molecule could be destroyed by many other means, like: ion-molecular reactions or by the effect of cosmic rays. Ion-molecular reaction rates are computed by using the capture theories. We have also included the obtained rate coefficients into our large gas-grain chemical network to study the chemical evolution of these species in various interstellar conditions. Formation of one of the isotopologue(DCOCN) of HCOCN is also studied. Our study predicts the possibility of finding HCOCN and DCOCN in the ice phase with a reasonably high abundance. In order to detect HCOCN or DCOCN in various interstellar environments, it is necessary to know the spectroscopic properties of these molecules. To this effect, we carried out quantum chemical calculations to find out different spectral parameters of HCOCN for the transition in electronic, infrared and rotational modes. We clearly show how the isotopic substitution (DCOCN) plays a part in the vibrational progressions of HCOCN.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

↑