Exoplanets with substantial Hydrogen/Helium atmospheres have been discovered in abundance, many residing extremely close to their parent stars. The extreme irradiation levels these atmospheres experience causes them to undergo hydrodynamic atmospheric escape. Ongoing atmospheric escape has been observed to be occurring in a few nearby exoplanet systems through transit spectroscopy both for hot Jupiters and lower-mass super-Earths/mini-Neptunes. Detailed hydrodynamic calculations that incorporate radiative transfer and ionization chemistry are now common in one-dimensional models, and multi-dimensional calculations that incorporate magnetic-fields and interactions with the interstellar environment are cutting edge. However, there remains very limited comparison between simulations and observations. While hot Jupiters experience atmospheric escape, the mass-loss rates are not high enough to affect their evolution. However, for lower mass planets atmospheric escape drives and controls their evolution, sculpting the exoplanet population we observe today.

中文翻译：

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大气逃逸和近距离系外行星的演化

已经发现了大量具有大量氢/氦大气的系外行星，其中许多离它们的母星非常近。这些大气所经历的极端辐射水平导致它们经历流体动力学大气逃逸。通过对热木星和低质量超级地球/迷你海王星的凌日光谱，已经观察到在一些附近的系外行星系统中发生了正在进行的大气逃逸。结合辐射转移和电离化学的详细流体动力学计算现在在一维模型中很常见，而结合磁场和与星际环境相互作用的多维计算则是最前沿的。然而，模拟和观察之间的比较仍然非常有限。当炽热的木星经历大气逃逸时，质量损失率不足以影响它们的进化。然而，对于质量较低的行星，大气逃逸驱动并控制了它们的演化，塑造了我们今天观察到的系外行星种群。