论文标题
从地球样到超级地球型系外行星的恒星驱动的氢气驱动的演变
Stellar Driven Evolution of Hydrogen-Dominated Atmospheres from Earth-Like to Super-Earth-Type Exoplanets
论文作者
论文摘要
在本章中，我们介绍了超球星大气的进化研究结果。尽管这些方法适用于所有类型的系外行星，但我们主要专注于子至超级域。我们考虑热损失过程和非热损耗过程。热损耗机制的类型取决于所谓的逃生参数$β$，这是粒子的重力与其热能的比例。尽管$β$正在减少，但系外行星从经典牛仔裤转换为改装牛仔裤，最后转到吹式逃生机制。在吹吹动期间，大多数大气颗粒都会丢弃足够的能量以逃避地球的重力场。这导致极端的气体损失。 尽管非热损失永远不会超过吹式逃脱，但对于牛仔裤型逃逸相对较弱的行星而言，它们至关重要。从非热逃逸机制的多样性中，在本章中，我们关注离子拾取，并讨论其他损失机制的重要性。本章的总体结论是，逃生过程强烈影响外部行星的演变，并确定地球是否由于侵蚀过程而失去了大气，或者相反，该行星是小型纽扣型体，这可能不可被视为我们所知的潜在栖息地。
In the present chapter we present the results of evolutionary studies of exoplanetary atmospheres. We mostly focus on the sub- to super-Earth domain, although these methods are applicable to all types of exoplanets. We consider both thermal and nonthermal loss processes. The type of thermal loss mechanism depends on so-called escape parameter $β$, which is the ratio of the gravitational energy of a particle to its thermal energy. While $β$ is decreasing, an exoplanet switches from classical Jeans to modified Jeans and finally to blow-off escape mechanisms. During blow-off the majority of the atmospheric particles dispose of enough energy to escape the planet's gravity field. This leads to extreme gas losses. Although nonthermal losses never exceed blow-off escape, they are of significant importance for planets with relatively weak Jeans-type escape. From the diversity of nonthermal escape mechanisms, in the present chapter we focus on ion pickup and discuss the importance of other loss mechanisms. The general conclusion of the chapter is, that escape processes strongly shape the evolution of the exoplanets and determine, if the planet loses its atmosphere due to erosion processes or, on the contrary, stays as mini-Neptune type body, which can probably not be considered as a potential habitat as we know it.
