Dynamics of pebbles in the vicinity of a growing planetary embryo: hydro-dynamical simulations
Dynamics of pebbles in the vicinity of a growing planetary embryo: hydro-dynamical simulations
复制标题
正在生长的行星胚胎附近的卵石动力学：流体动力学模拟
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
D. Nesvorný
中科院分区：
文献类型：
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作者：
A. Morbidelli;D. Nesvorný
上下文理解巨行星核心的生长是一个难题。最近，Lambrechts & Johansen（2012，A&A，544，A32，LJ12）提出了一个新的模型，其中核心通过卵石大小的物体的吸积而增长，因为后者由于气体阻力而向星星漂移。目标。我们调查的动力学卵石大小的物体在附近的行星胚胎的1和5个地球质量和由此产生的吸积率。方法.我们使用流体动力学模拟，其中胚胎影响气体的动力学和卵石遭受气体阻力根据当地的气体密度和速度。结果在行星胚胎附近的卵石动力学是不平凡的，它的变化显着与卵石的大小。然而，我们测量的胚胎的吸积率是在一个数量级的速率估计在LJ 12，并倾向于他们的值与增加卵石的大小。结论. LJ12的模型有可能解释巨行星核心的快速增长。然而，实际的吸积率取决于圆盘中卵石大小的物体的表面密度，这是未知的。
Context. Understanding the growth of the cores of giant planets is a difficult problem. Recently, Lambrechts & Johansen (2012, A&A, 544, A32, LJ12) proposed a new model in which the cores grow by the accretion of pebble-size objects, as the latter drift towards the star due to gas drag. Aims. We investigate the dynamics of pebble-size objects in the vicinity of planetary embryos of 1 and 5 Earth masses and the resulting accretion rates. Methods. We use hydrodynamical simulations, in which the embryo influences the dynamics of the gas and the pebbles suffer gas drag according to the local gas density and velocities. Results. The pebble dynamics in the vicinity of the planetary embryo is non-trivial, and it changes significantly with the pebble size. Nevertheless, the accretion rate of the embryo that we measure is within an order of magnitude of the rate estimated in LJ 12 and tends to their value with increasing pebble-size. Conclusions. The model by LJ12 has the potential to explain the rapid growth of giant planet cores. The actual accretion rates however, depend on the surface density of pebble size objects in the disk, which is unknown to date.