How the formation of Neptune shapes the Kuiper belt
How the formation of Neptune shapes the Kuiper belt
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海王星的形成如何塑造柯伊伯带
DOI：
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
A. Mustill
中科院分区：
文献类型：
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作者：
S. Pirani;A. Johansen;A. Mustill
在原行星盘的气相期间，通过流体动力学模拟预测了巨行星的向内迁移。该现象也被用来解释共振和近共振系外行星系统的结构。早期的向内迁移也可能影响了我们的太阳系，并塑造了不同的小行星库。在这项研究中，我们将探索巨行星的早期向内迁移如何塑造柯伊伯带。我们测试了不同的场景，只有海王星和天王星，并与所有四个巨大的行星，包括一些模型与随后的外向星子驱动的海王星迁移后的气体扩散。我们发现，即使海王星和天王星根本不迁移或只向内迁移，物体也会填充平均运动共振。当行星被固定时，星子只是暂时地粘在平均运动共振上，而向内迁移产生了一个新的通道来填充共振，而不会引起收敛迁移。然而，在这些情况下，很难填充不穿过星子盘的平均运动共振（如2：1和5：2），并且缺乏穿过海王星轨道的共振KBO。这些海王星穿越者是海王星向外迁移的明确标志。海王星的起始位置和生长速率关系到经典柯伊伯带区域受到邻近区域的污染。当把所有的巨行星都包括在内时，热经典行星的偏心率和倾角空间以及分散盘区域变得更加密集。与海王星的5：2共振随着海王星更深的向内迁移而变得越来越多。然而，整体倾斜度分布仍然比观测值窄，柯伊伯带人口模型通常就是这种情况。
Inward migration of giant planets is predicted by hydrodynamical simulations during the gas phase of the protoplanetary disc. The phenomenon is also invoked to explain resonant and near-resonant exoplanetary system structures. The early inward migration may also have affected our Solar System and sculpted its different minor planet reservoirs. In this study we explore how the early inward migration of the giant planets shapes the Kuiper Belt. We test different scenarios with only Neptune and Uranus and with all the four giant planets, including also some models with the subsequent outward planetesimal-driven migration of Neptune after the gas dispersal. We find objects populating mean motion resonances even when Neptune and Uranus do not migrate at all or only migrate inwards. When the planets are fixed, planetesimals stick only temporarily to the mean motion resonances, while inwards migration yields a new channel to populate the resonances without invoking convergent migration. In these cases, however, it is hard to populate mean motion resonances that do not cross the planetesimal disc (such as 2:1 and 5:2) and there is a lack of resonant KBOs that cross Neptune’s orbit. These Neptune crossers are an unambiguous signature of the outward migration of Neptune. The starting position and the growth rate of Neptune matters for the contamination of the classical Kuiper belt region from neighbouring regions. The eccentricity and inclination space of the hot classicals and the scattered disc region become much more populated when all the giant planets are included. The 5:2 resonance with Neptune becomes increasingly populated with deeper inward migrations of Neptune. The overall inclination distribution, however, is still narrower than from observations, as is generally the case for Kuiper belt population models.