Influence of different host stars upon the atmospheres of planets at the boundary of rocky and gas planets

系外行星科学的一个主要问题是确定岩石行星和气体行星边界上的行星的性质。为了实现这一目标，需要了解决定它们的大气和光谱外观的关键过程。如果这些行星围绕着附近明亮的恒星运行，那么它们的大气层就可以被当前和不久的将来的仪器探测到。这些行星围绕不同类型的恒星运行，它们的大气层的来源可能是不同的，例如由恒星星云的吸积，冰的升华和/或从内部释放气体形成。因此，该项目旨在了解不同的主恒星和大气起源对海王星质量半径范围内行星大气及其光谱外观的影响。它将决定是否以及哪些光谱特征可以用来区分主要是岩石行星和气体行星。为了研究不同恒星的影响，需要一个耦合的大气模型来考虑不同恒星辐照对大气温度和成分的影响。本文将建立一个新的耦合大气模式，利用逐行辐射传输模式，通过辐射和对流能量输运计算大气温度。该辐射对流模型将与平衡和非平衡化学模型耦合，以考虑温度结构和恒星辐射对大气化学成分的影响。根据所得的大气剖面，将确定这些行星的光谱外观以及当前和未来仪器对光谱特征的可探测性。

A major issue in exoplanet science is to determine the nature of planets at the boundary of rocky and gaseous planets. To achieve this, the key processes which determine their atmospheres and their spectral appearance need to be understood. The atmospheres of these planets are accessible by current and near future instruments if they orbit nearby, bright stars. These planets orbit different types of stars and the origin of their atmospheres may be diverse, formed e.g. by accretion from the stellar nebula, sublimation of ices and/or outgassing from the interior.This project therefore aims at understanding the influence of different host stars and atmospheric origins upon the atmospheres of planets in the sub-Neptunian mass-radius regime and their spectral appearance. It will determine whether and which spectral signatures can be used to distinguish between mainly rocky and gaseous planets.To study the impact of different stars a coupled atmosphere model is needed hat accounts for the influence of different stellar irradiation upon the atmospheric temperatures and composition. A new coupled atmosphere model will be developed which calculates the atmospheric temperatures via radiative and convective energy transport, utilizing a line-by-line radiative transfer model. This radiative-convective model will be coupled to equilibrium and non-equilibrium chemistry models to consider the impact of the temperature structure and the stellar irradiation upon the atmospheric chemical composition. From the resulting atmospheric profiles the spectral appearance of these planets and the detectability of spectral features with current and future instruments will be determined.