论文标题
揭示多云的系外行星：云模型选择对检索解决方案的影响
Unveiling cloudy exoplanets: the influence of cloud model choices on retrieval solutions
论文作者
论文摘要
近年来，很明显，大部分大气中有大量的过境系外行星中存在某种形式的气溶胶。过境光谱法 - 主要是热木星，但也是一些较小的行星 - 为此提供了证据，以光谱的光学部分的陡峭向下斜率从蓝色到红色的形式，并且整个过程中都有柔和的气体吸收特征。因此，试图限制系外行星大气组成的检索研究必须解释气溶胶的存在。但是，云和危险是复杂的物理现象，目前可用的过境光谱使我们只能限制其某些特性。因此，在检索模型中，气溶胶的表示要求仅通过几个参数来描述它们，并且在文献中以多种方式进行。在这里，我研究了系外星空气溶胶的一系列参数及其对热木星传输光谱HD 189733B和HD 209458B的探索的影响。我发现，无论使用哪种参数化，我都会发现云/阴霾本身的云/阴霾本身一致，并且实际上使用多种方法提供了更全面的图片。检索到的H2O的丰度也对气溶胶的假设也非常强大。我还发现有力的证据表明，HD 209458B上的气溶胶覆盖不到终结者区域的一半，而HD 189733B的情况不太清楚。
In recent years, it has become clear that a substantial fraction of transiting exoplanets have some form of aerosol present in their atmospheres. Transit spectroscopy - mostly of hot Jupiters, but also of some smaller planets - has provided evidence for this, in the form of steep downward slopes from blue to red in the optical part of the spectrum, and muted gas absorption features throughout. Retrieval studies seeking to constrain the composition of exoplanet atmospheres must therefore account for the presence of aerosols. However, clouds and hazes are complex physical phenomena, and the transit spectra that are currently available allow us to constrain only some of their properties. Therefore, representation of aerosols in retrieval models requires that they are described by only a few parameters, and this has been done in a variety of ways within the literature. Here, I investigate a range of parameterisations for exoplanet aerosol and their effects on retrievals from transmission spectra of hot Jupiters HD 189733b and HD 209458b. I find that results qualitatively agree for the cloud/haze itself regardless of the parameterisation used, and indeed using multiple approaches provides a more holistic picture; the retrieved abundance of H2O is also very robust to assumptions about aerosols. I also find strong evidence that aerosol on HD 209458b covers less than half of the terminator region, whilst the picture is less clear for HD 189733b.
