论文标题
大气分子的非本地热平衡光谱
Non-Local thermal equilibrium spectra of atmospheric molecules for exoplanets
论文作者
论文摘要
在这里，我们介绍了非LTE对分子集合的外球星光谱的影响，这是研究系外界大气的关键：水，甲烷，碳一氧化碳和氧化钛。这些分子被选为不同光谱范围（IR和紫外），分子类型（双原子和多原子）和光谱类型（电子和RO振动）的例子；研究了不同振动带在形成不同的非LTE光谱特征中的重要性。最值得注意的是，这种区分LTE和非LTE案例的关键频谱签名包括：对于CH4，3.15 $μ$ m频段区域；对于H2O，2.0 $μ$ m和2.7 $ $ m $ m频段区域；对于TIO，在0.5至0.75 $μm之间的频段中强度有很大变化；以及5至6 $μ$ m之间的唯一CO签名。该分析基于Exomol横截面，并利用Exomol数据库中这些分子线列表的广泛振动分配。我们使用经验动机的双温度treanor模型检查了与WASP-12B和WASP-76B一致的条件下的LTE和非LTE横截面。此外，我们使用TAUREX 3大气建模代码对H2O的传输光谱进行了简单的远期模型模拟。
Here we present a study of non-LTE effects on the exoplanetary spectra of a collection of molecules which are key in the investigation of exoplanet atmospheres: water, methane, carbon monoxide and titanium oxide. These molecules are chosen as examples of different spectral ranges (IR and UV), molecular types (diatomics and polyatomics) and spectral types (electronic and ro-vibrational); the importance of different vibrational bands in forming distinct non-LTE spectral features are investigated. Most notably, such key spectral signatures for distinguishing between the LTE and non-LTE cases include: for CH4 the 3.15 $μ$m band region; for H2O the 2.0 $μ$m and 2.7 $μ$m band regions; for TiO, a strong variation in intensity in the bands between 0.5 and 0.75 $μ$m; and a sole CO signature between 5 and 6 $μ$m. The analysis is based on the ExoMol cross sections and takes advantage of the extensive vibrational assignment of these molecular line lists in the ExoMol database. We examine LTE and non-LTE cross sections under conditions consistent with those on WASP-12b and WASP-76b using the empirically motivated bi-temperature Treanor model. In addition, we make a simplistic forward model simulation of transmission spectra for H2O in the atmosphere of WASP-12b using the TauREx 3 atmospheric modelling code.
