The Formation of Planetary Proto-Atmospheres

背景：在它们的形成过程中，原行星变得足够大，可以通过引力将它们出生的圆盘中的气体结合起来。对于像木星这样的巨行星，岩石或冰的核心变得如此巨大，以至于引发了气体的失控吸积。较小的行星，如海王星，地球和超级地球，只能结合有限数量的气体。因此，气体吸积在磁盘嵌入阶段的物理细节产生一个独特的属性所观察到的行星distribution.Methods：行星原大气层的形成和早期演变，嵌入在他们的纳塔尔盘，应使用国家的最先进的辐射流体动力学建模进行研究。我们将在二维和三维模拟中包括流体动力学和热力学效应。此外，在以行星为中心的球坐标系中进行这些模拟，使我们能够以非常高的分辨率解决大气层积聚的物理问题。局部框架的初始和边界条件代表大规模的磁盘流，将从先前的全球磁盘模拟中提取，在球坐标系中进行，主星星位于网格的原点。我们将提取大气质量，它的旋转轮廓，辐射冷却以及气体补充时间尺度作为核心，磁盘，以及周围气体和尘埃的光学性质。由此，我们研究了在何种条件下形成的大气接近稳态或准稳态系统。此外，我们还可以具体地测试这一假设，即储存在核心中的热量和/或气流的不对称结构是否会阻止超级地球的大气层坍塌。简历：行星原大气层的流体动力学和热力学将在其形成和早期演变的直接高分辨率建模中进行研究。遵循局部方法使我们能够以前所未有的细节确定小尺度物理。研究结果将揭示超级地球大气层的形成和稳定性。

Context: During their formation, proto-planets become massive enough to gravitationally bind gas from the disks they are born in. For giant planets such as Jupiter, the rocky or icy core becomes so massive that it triggers a runaway accretion of gas. Smaller planets such as Neptune, Earth, and super-Earths instead are only able to bind a limited amount of gas. Hence, the physical details of gas accretion in the disk-embedded phase yields a distinctive attribute of the observed planetary distribution.Methods: The formation and early evolution of planetary proto-atmospheres, embedded in their natal disk, shall be investigated using state-of-the-art radiation-hydrodynamical modeling. We will include both - the hydrodynamic as well as the thermodynamic - effects in two- and three-dimensional simulations. Moreover, conducting these simulations in a local frame in planeto-centric spherical coordinates with the planet at the origin of the grid, allows us to resolve the physics of the atmospheric build-up in very high resolution. Initial and boundary conditions for the local frame, representing the large-scale disk flow, will be extracted from preceding global disk simulations, performed in spherical coordinates with the host star at the origin of the grid.Aims: We will extract the atmospheric mass, its rotation profile, and the radiative cooling as well as the gas replenishing timescale as a function of the core, the disk, and the optical properties of the surrounding gas and dust. From that, we investigate under which condition the forming atmosphere approaches a steady state or quasi-stationary system. Additionally, we can specifically test the hypothesis, whether the thermal heat stored in the core and/or the asymmetric structure of the gas flow prevents the atmospheres of super-Earths from collapsing. Resume: The hydrodynamics and thermodynamics of planetary proto-atmospheres will be investigated in direct high-resolution modeling of their formation and early evolution. Following a local approach allows us to determine the small-scale physics in unprecedented detail. The research outcome will shed light on the formation and stability of super-Earth atmospheres.