论文标题
通过巨大冲击产生的水蒸气磁盘的进化，乌拉尼亚卫星形成
Uranian Satellite Formation by Evolution of a Water Vapor Disk Generated by a Giant Impact
论文作者
论文摘要
鉴于其旋转轴倾斜98度，因此天王星冰上的天王星可能受到巨大的冲击。它的卫星系统同样倾斜，并且表明它是由于影响而形成的。但是，影响模拟预测的磁盘通常具有一个较小的尺寸，并且质量比目前观察到的系统大两个阶。在这里，我们通过理论模型表明，乌拉尼亚卫星的形成受影响生成的磁盘的演变来调节。由于水冰的汽化温度较低，天王星和撞击器都被认为是冰为主的，因此我们可以得出结论，撞击生成的磁盘大多数是蒸发的。我们预测，磁盘损失了大量的水蒸气质量并扩散到当前系统的水平，直到磁盘冷却得足以使冰冷凝并开始冰颗粒开始。从预测的冷凝冰的分布中，我们的N体模拟能够重现观察到的乌拉尼亚卫星的质量轨道构型。这种情况与地球月亮的巨型影响模型形成鲜明对比，地球的月球大约一半紧凑，撞击生成，固体或液体磁盘立即在撞击时立即纳入月球。
The ice-giant planet Uranus likely underwent a giant impact, given that its spin axis is tilted by 98 degrees. That its satellite system is equally inclined and prograde suggests that it was formed as a consequence of the impact. However, the disks predicted by the impact simulations generally have sizes one order smaller and masses two orders larger than those of the observed system at present. Here we show, by means of a theoretical model, that the Uranian satellite formation is regulated by the evolution of the impact-generated disk. Because the vaporization temperature of water ice is low and both Uranus and the impactor are assumed to be ice-dominated, we can conclude that the impact-generated disk has mostly vaporized. We predict that the disk lost a significant amount of water vapour mass and spread to the levels of the current system until the disk cooled down enough for ice condensation and accretion of icy particles to begin. From the predicted distribution of condensed ices, our N-body simulation is able to reproduce the observed mass-orbit configuration of Uranian satellites. This scenario contrasts with the giant-impact model for the Earth's Moon, in which about half of the compact, impact-generated, solid or liquid disk is immediately incorporated into the Moon on impact.
