A CHEMICAL KINETICS NETWORK FOR LIGHTNING AND LIFE IN PLANETARY ATMOSPHERES
A CHEMICAL KINETICS NETWORK FOR LIGHTNING AND LIFE IN PLANETARY ATMOSPHERES
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DOI：
10.3847/0067-0049/224/1/9
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发表时间：
2015-10
期刊：
影响因子：
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通讯作者：
P. Rimmer;Christiane Helling
中科院分区：
文献类型：
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作者：
P. Rimmer;Christiane Helling
关于行星和行星外环境中的益生菌化学，有许多悬而未决的问题。越来越多的已知系外行星和其他超冷的恒星下天体促使人们渴望探测太阳系外的生命和生命前化学物质。我们提供了一个从头开始构建的离子中性化学网络，Stand2015，它在100到3万K的温度范围内准确地处理氢、氮、碳和氧化学，包括甘氨酸和其他有机分子的形成路径。直到H6C2N2O3时，网络是完整的。Stand2015使用一个简单的一维光化学/扩散代码，成功地与HD 209458b、木星和今天的地球的大气化学模型进行了测试。我们对早期地球的研究结果与卡斯廷对二氧化碳、氢气、一氧化碳和氧气的研究结果一致，但对水和原子氧的研究结果不一致。我们使用该网络来模拟一个实验，其中不同的化学初始条件被紫外线照射。我们的模拟结果是，当存在更多的氨和甲烷时，会产生更多甘氨酸。在没有任何分子氮和氧的情况下，几乎不会产生甘氨酸。这表明，如果气体还原得太强烈，甘氨酸的产生就会受到抑制。文中还讨论了化学动力学网络的可能应用和局限性。
There are many open questions about prebiotic chemistry in both planetary and exoplanetary environments. The increasing number of known exoplanets and other ultra-cool, substellar objects has propelled the desire to detect life and prebiotic chemistry outside the solar system. We present an ion–neutral chemical network constructed from scratch, Stand2015, that treats hydrogen, nitrogen, carbon, and oxygen chemistry accurately within a temperature range between 100 and 30,000 K. Formation pathways for glycine and other organic molecules are included. The network is complete up to H6C2N2O3. Stand2015 is successfully tested against atmospheric chemistry models for HD 209458b, Jupiter, and the present-day Earth using a simple one-dimensional photochemistry/diffusion code. Our results for the early Earth agree with those of Kasting for CO2, H2, CO, and O2, but do not agree for water and atomic oxygen. We use the network to simulate an experiment where varied chemical initial conditions are irradiated by UV light. The result from our simulation is that more glycine is produced when more ammonia and methane is present. Very little glycine is produced in the absence of any molecular nitrogen and oxygen. This suggests that the production of glycine is inhibited if a gas is too strongly reducing. Possible applications and limitations of the chemical kinetics network are also discussed.