Oort cloud and Scattered Disc formation during a late dynamical instability in the Solar System
Oort cloud and Scattered Disc formation during a late dynamical instability in the Solar System
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DOI：
10.1016/j.icarus.2013.03.012
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发表时间：
2012-05
期刊：
影响因子：
3.2
通讯作者：
R. Brasser;A. Morbidelli
中科院分区：
文献类型：
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作者：
R. Brasser;A. Morbidelli
外太阳系动力学演化的一个突出问题是关于奥尔特云（OC）和散射盘（SD）之间观测到的人口比：观测表明这个比例在100和1000之间，但同时产生这两个水库的模拟一致地产生了10的数量级。在这里，我们强调，在OC和SD的人口推断从观测到的新的长周期彗星（LPC）和彗星家族彗星（JFC），比一些参考总星等亮通量。然而，在模拟SD和OC形成过程中估计的人口比例是指大于给定大小的物体。有多个迹象表明LPC本质上比JFC更亮，即LPC小于具有相同总绝对星等的JFC。考虑到这一点，我们根据邓肯和列维森（1997）的模拟结果修正了SD/JFC的种群比，然后从观察结果中推断出OC和SD之间的大小限制种群比为44-34+54。这大约是我们在模拟中获得的值12±1的四倍，其中OC和SD同时形成，而行星根据所谓的“尼斯模型”进化。因此，我们仍然有模型和“观察”之间的差异，但协议不能被零假设拒绝。
One of the outstanding problems of the dynamical evolution of the outer Solar System concerns the observed population ratio between the Oort cloud (OC) and the Scattered Disc (SD): observations suggest that this ratio lies between 100 and 1000 but simulations that produce these two reservoirs simultaneously consistently yield a value of the order of 10. Here we stress that the populations in the OC and SD are inferred from the observed fluxes of new long period comets (LPCs) and Jupiter-family comets (JFCs), brighter than some reference total magnitude. However, the population ratio estimated in the simulations of formation of the SD and OC refers to objects bigger than a given size. There are multiple indications that LPCs are intrinsically brighter than JFCs, i.e. an LPC is smaller than a JFC with the same total absolute magnitude. When taking this into account we revise the SD/JFC population ratio from our simulations relative to Duncan and Levison (1997), and then deduce from the observations that the size-limited population ratio between the OC and the SD is 44-34+54. This is roughly a factor of four higher than the value 12±1 that we obtain in simulations where the OC and the SD form simultaneously while the planets evolve according to the so-called ‘Nice model’. Thus, we still have a discrepancy between model and ‘observations’, but the agreement cannot be rejected by the null hypothesis.