Not a Simple Relationship between Neptune’s Migration Speed and Kuiper Belt Inclination Excitation
Not a Simple Relationship between Neptune’s Migration Speed and Kuiper Belt Inclination Excitation
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DOI：
10.3847/1538-3881/ab2639
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发表时间：
2019-05
期刊：
影响因子：
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通讯作者：
K. Volk;R. Malhotra
中科院分区：
文献类型：
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作者：
K. Volk;R. Malhotra
我们对太阳系中的巨型行星迁移进行了数值模拟，并研究了行星迁移的速度如何影响向外散射并随后被捕获到海王星 3:2 平均运动共振（冥王星）的小天体（测试粒子）群体以及热门的经典柯伊伯带群体的倾角。我们没有发现测试粒子倾斜激发程度与 5-50 Myr 范围内的 e 折叠行星迁移时间尺度之间存在一致的关系。我们的结果为内斯沃尼的发现提供了一个反例，即冥王星和热经典倾角随着海王星迁移的电子折叠时间尺度的增加而显着增加。我们认为，这些不同的结果可能是由于巨行星在迁移期间和之后的世俗结构不同所致。行星初始条件的微小变化以及行星迁移数值实现的差异可能会导致行星倾角世俗模式的不同幅度，这可能导致模拟中测试粒子的最终倾角分布不同。我们的结论是，观测到的柯伊伯带天体的大倾角色散并不要求海王星的迁移缓慢； e折叠时间尺度为5、10、30和50 Myr的行星迁移都可以产生类似于观测到的冥王星和热经典星群的倾角离散度，倾角激发程度和迁移速度之间没有相关性。
We present numerical simulations of giant planet migration in our solar system and examine how the speed of planetary migration affects inclinations in the resulting population of small bodies (test particles) scattered outward and subsequently captured into Neptune’s 3:2 mean motion resonance (the Plutinos), as well as the hot classical Kuiper Belt population. We do not find a consistent relationship between the degree of test particle inclination excitation and e-folding planet migration timescales in the range 5–50 Myr. Our results present a counterexample to Nesvorný's finding that the Plutino and hot classical inclinations showed a marked increase with increasing e-folding timescales for Neptune’s migration. We argue that these differing results are likely due to differing secular architectures of the giant planets during and after migration. Small changes in the planets’ initial conditions and differences in the numerical implementation of planet migration can result in different amplitudes of the planets’ inclination secular modes, and this can lead to different final inclination distributions for test particles in the simulations. We conclude that the observed large inclination dispersion of Kuiper Belt objects does not require Neptune’s migration to be slow; planetary migration with e-folding timescales of 5, 10, 30, and 50 Myr can all yield inclination dispersions similar to the observed Plutino and hot classical populations, with no correlation between the degree of inclination excitation and migration speed.