arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1607.04062astro-ph.EP
收藏

化学动力学一致性计算对高温超导体压温分布和发射光谱的影响

The Effects of Consistent Chemical Kinetics Calculations on the Pressure-Temperature Profiles and Emission Spectra of Hot Jupiters

Benjamin Drummond, Pascal Tremblin, Isabelle Baraffe, David S. Amundsen, Nathan J. Mayne, Olivia Venot, Jayesh Goyal

摘要:

在这项工作中,我们调查的影响,计算非平衡化学丰度一致的温度结构的大气中的高辐射,接近气体巨系外行星。化学动力学模型在文献中被广泛用于研究热木星大气的化学成分,这些大气预计会通过垂直混合和光化学等过程被驱离化学平衡。迄今为止,所有这些模型都使用压力-温度(P-T)分布作为固定的模型输入。这导致化学与大气的辐射和热特性脱钩,尽管在自然界中它们是错综复杂地联系在一起的。我们使用一个一维的辐射对流平衡模型,ATMO,其中包括一个复杂的化学方案来计算P-T配置文件是完全符合非平衡化学丰度,包括垂直混合和光化学。我们的主要结论是,在强化学不平衡的情况下,一致的计算可以导致高达100 K的P-T曲线的差异相比,假设化学平衡的P-T曲线。这种温度变化反过来又会对化学丰度本身以及模拟的发射光谱产生重要影响。特别是,我们发现,执行化学动力学计算一致,可以减少非平衡化学的整体影响,可观察到的发射光谱的热闪烁。因此,从不一致的模型中得出的模拟观测结果可能会产生错误的解释。我们表明,这种行为是由于不一致的模型违反了大气的能量收支平衡。

英文摘要:

In this work we investigate the impact of calculating non-equilibrium chemical abundances consistently with the temperature structure for the atmospheres of highly-irradiated, close-in gas giant exoplanets. Chemical kinetics models have been widely used in the literature to investigate the chemical compositions of hot Jupiter atmospheres which are expected to be driven away from chemical equilibrium via processes such as vertical mixing and photochemistry. All of these models have so far used pressure--temperature (P-T) profiles as fixed model input. This results in a decoupling of the chemistry from the radiative and thermal properties of the atmosphere, despite the fact that in nature they are intricately linked. We use a one-dimensional radiative-convective equilibrium model, ATMO, which includes a sophisticated chemistry scheme to calculate P-T profiles which are fully consistent with non-equilibrium chemical abundances, including vertical mixing and photochemistry. Our primary conclusion is that, in cases of strong chemical disequilibrium, consistent calculations can lead to differences in the P-T profile of up to 100 K compared to the P-T profile derived assuming chemical equilibrium. This temperature change can, in turn, have important consequences for the chemical abundances themselves as well as for the simulated emission spectra. In particular, we find that performing the chemical kinetics calculation consistently can reduce the overall impact of non-equilibrium chemistry on the observable emission spectrum of hot Jupiters. Simulated observations derived from non-consistent models could thus yield the wrong interpretation. We show that this behaviour is due to the non-consistent models violating the energy budget balance of the atmosphere.

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。

↑