Circum-planetary accretion disks

在行星形成过程的早期阶段，非常年轻的原行星仍然镶嵌在它们形成的恒星周围的圆盘中。盘-行星相互作用的数值流体动力学模拟表明，原行星积累的质量首先围绕它循环，然后通过一个绕行星的子盘以几乎开普勒式的旋转被吸积。为了进一步了解原行星的吸积过程，对环绕行星吸积盘进行高分辨率的数值模拟是必不可少的。我们首次提出对这些绕行星子盘进行详细的多维流体动力学模拟，以确定它们的结构和演化。从计算中，我们将获得关于原行星核心的生长速度、角动量演变以及行星形成的时间尺度的重要信息。环绕行星的圆盘可能达到相对较高的温度，但位于周围较冷的环绕恒星的圆盘内。从我们对绕行星盘参数空间的详细研究中，我们期望对行星系统早期形成阶段的观测特性也有有趣的见解。

During the early stages of the planet formation process very young protoplanets are still embedded in the circum-stellar disk from which they formed. Numerical hydrodynamic simulations of disk-planet interaction have shown that the mass accumulated by the protoplanet first circulates around it, and is then accreted via a circum-planetary sub-disk in almost Keplerian rotation.In order to further understand the accretion process onto the protoplanet, high resolution numerical simulations of the circum-planetary accretion disk are essential. We propose to perform for the first time detailed multi-dimensional hydrodynamic simulations of these circum-planetary sub-disks to determine their structure and evolution. From the calculations we will gain important information about the growth rate of protoplanetary cores, their angular momentum evolution and, thus, the time scale of planet formation.Circum-planetary disks may reach comparatively high temperatures, but are located within the surrounding cooler circum-stellar disk. From our detailed investigation of the circum-planetary disk parameter space we expect also interesting insight concerning observational properties of planetary systems in their early formation phase.