The UMIST Database for Astrochemistry 2022
The UMIST Database for Astrochemistry 2022
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DOI：
10.1051/0004-6361/202346908
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发表时间：
2024-02-09
影响因子：
6.5
通讯作者：
Markwick，A. J.
中科院分区：
文献类型：
--
作者：
Millar，T. J.;Walsh，C.;Markwick，A. J.
上下文。详细的天体化学模型是解释星际和星周分子观测的关键组成部分，因为它们允许推断气体的重要物理特性及其演化历史。我们更新了最广泛使用的天体化学数据库之一，以反映速率系数的实验和理论估计的进展，并响应自2013年发布以来在太空中检测到的分子数量的大量增加。我们介绍了UMIST天体化学数据库（UDfA）的第六版，这是描述星际和星周分子合成的气相化学的主要扩展。自上次发布以来，我们进行了一次主要的文献回顾，使反应数量增加了40%以上，达到8767种，物种数量增加了55%以上，达到737种。我们特别尝试将过去十年中在太空中发现的许多新物种包括在内，包括那些来自QUIJOTE和GOTHAM调查的物种，并提供原始数据来源的参考。我们使用该数据库来研究适合于TMC-1中富o和富c条件的气相化学，以及富c的AGB星IRC+10216的星周包膜，并确定仅气相模型的成功和失败。这次更新是对UDfA数据库的重大改进。对于黑云和富含c的星周包层模型，计算结果与观测到的物种丰度的60%在一个数量级内匹配。然而，有许多被探测到的物种没有被包括在模型中，要么是因为它们的气相化学性质未知，要么是因为它们可能是通过冰粒表面反应形成的。未来的实验室和理论工作需要将这些物种纳入反应网络。
Context. Detailed astrochemical models are a key component to interpret the observations of interstellar and circumstellar molecules since they allow important physical properties of the gas and its evolutionary history to be deduced.Aims. We update one of the most widely used astrochemical databases to reflect advances in experimental and theoretical estimates of rate coefficients and to respond to the large increase in the number of molecules detected in space since our last release in 2013.Methods. We present the sixth release of the UMIST Database for Astrochemistry (UDfA), a major expansion of the gas-phase chemistry that describes the synthesis of interstellar and circumstellar molecules. Since our last release, we have undertaken a major review of the literature which has increased the number of reactions by over 40% to a total of 8767 and increased the number of species by over 55% to 737. We have made a particular attempt to include many of the new species detected in space over the past decade, including those from the QUIJOTE and GOTHAM surveys, as well as providing references to the original data sources.Results. We use the database to investigate the gas-phase chemistries appropriate to both O-rich and C-rich conditions in TMC-1 and to the circumstellar envelope of the C-rich AGB star IRC+10216 and identify successes and failures of gas-phase only models.Conclusions. This update is a significant improvement to the UDfA database. For both the dark cloud and C-rich circumstellar envelope models, calculations match around 60% of the abundances of observed species to within an order of magnitude. There are a number of detected species, however, that are not included in the model either because their gas-phase chemistry is unknown or because they are likely formed via surface reactions on icy grains. Future laboratory and theoretical work is needed to include such species in reaction networks.