Planetesimal clearing and size-dependent asteroid retention by secular resonance sweeping during the depletion of the solar nebula
Planetesimal clearing and size-dependent asteroid retention by secular resonance sweeping during the depletion of the solar nebula
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在太阳星云耗尽期间，通过长期共振扫描进行行星清除和大小相关的小行星保留
DOI：
10.3847/1538-4357/836/2/207
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发表时间：
2016-10
影响因子：
4.9
通讯作者：
M B N Kouwenhoven
中科院分区：
文献类型：
--
作者：
X C Zheng;D N C Lin;M B N Kouwenhoven
与太阳系其他地方相比，小行星主带区域重元素的分布异常低。观测调查还表明，小型（$ \le 50$公里大小）小行星的数量不足，比碰撞凝聚和破碎平衡所产生的单次幂律分布所预期的要低两个数量级。在这里，我们考虑了一种可能性，即在太阳星云耗尽期间，木星扫过主要小行星带时，原始小行星种群的大部分可能已经被木星的长期共振清除了。这种效应导致了小行星轨道偏心率的激发。同时，流体动力阻力和行星-盘潮汐相互作用分别有效地抑制了小于100公里大小和超月球大小的星子的偏心率。这些综合效应导致小行星的轨道衰减并从现在的主带区域（$\sim 2.1-3.3$ AU）中清除。中等大小（50到几百公里）的星子因此优先保留为靠近其诞生地的主带小行星，具有适度的渐近偏心。较小的小行星是后来发生的破坏性碰撞的碎片，正如现在的小行星家族所暗示的那样。这种情况为观测到的低表面密度和主带中小行星的大小分布提供了一个自然的解释。它也为类地行星的构造块的有限空间范围提供了解释，而不需要木星的广泛迁移。
The distribution of heavy elements is anomalously low in the asteroid main belt region compared with elsewhere in the solar system. Observational surveys also indicate a deficit in the number of small ($ \le 50$~km size) asteroids that is two orders of magnitude lower than what is expected from the single power-law distribution that results from a collisional coagulation and fragmentation equilibrium. Here, we consider the possibility that a major fraction of the original asteroid population may have been cleared out by Jupiter's secular resonance, as it swept through the main asteroid belt during the depletion of the solar nebula. This effect leads to the excitation of the asteroids' orbital eccentricities. Concurrently, hydrodynamic drag and planet-disk tidal interaction effectively damp the eccentricities of sub-100 km-size and of super-lunar-size planetesimals, respectively. These combined effects lead to the asteroids' orbital decay and clearing from the present-day main belt region ($\sim 2.1-3.3$~AU). The intermediate-size (50 to several hundreds of kilometers) planetesimals therefore preferentially remain as main belt asteroids near their birthplaces, with modest asymptotic eccentricities. The smaller asteroids are the fragments of subsequent disruptive collisions at later times as suggested by the present-day asteroid families. This scenario provides a natural explanation for both the observed low surface density and the size distribution of asteroids in the main belt. It also offers an explanation for the confined spatial extent of the terrestrial planet building blocks without the requirement of extensive migration of Jupiter.
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DOI：
10.1086/338504
发表时间：
2001-08
期刊：
The Astrophysical Journal
影响因子：
--
作者：
M. Lee;S. Peale
通讯作者：
M. Lee;S. Peale
DOI：
10.1086/426895
发表时间：
2004-09
期刊：
The Astrophysical Journal
影响因子：
--
作者：
A. Youdin;J. Goodman
通讯作者：
A. Youdin;J. Goodman
影响因子：
33.3
作者：
G. Wetherill
通讯作者：
G. Wetherill
DOI：
10.1086/316856
发表时间：
2000-12
期刊：
The Astronomical Journal
影响因子：
--
作者：
M. Nagasawa;S. Ida
通讯作者：
M. Nagasawa;S. Ida
DOI：
10.1086/519918
发表时间：
2007-05
期刊：
The Astrophysical Journal
影响因子：
--
作者：
Ji-lin Zhou;D. Lin;Yi-sui Sun
通讯作者：
Ji-lin Zhou;D. Lin;Yi-sui Sun