A Brief History of Trans-Neptunian Space
A Brief History of Trans-Neptunian Space
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跨海王星空间简史
DOI：
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发表时间：
2006
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通讯作者：
M. J. Holman
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作者：
Eugene Chiang;Y. Lithwick;R. Murray;M. Buie;W. Grundy;M. J. Holman
埃奇沃斯-柯伊伯带编码了外太阳系的动力学历史。柯伊伯带天体(KBO)见证了凝聚物理、行星轨道的演化和来自太阳邻域的外部扰动。我们批判性地回顾了当今带的观察到的性质以及为解释它们而设计的理论。理论是根据可能的事件时间线组织起来的。按照时间顺序，所描述的纪元包括(1)KBO在动态冷盘中的凝聚，(2)通过碎片碰撞和引力俘获形成双星KBO，(3)海王星质量行星(“寡头”)搅动KBO，(4)驱逐多余的寡头行星，(5)通过动力摩擦使轨道循环的剩余行星继续搅动KBO，(6)行星迁移和俘获共振KBO，(7)通过穿过开放星团中的恒星创建内奥尔特云，以及(8)最小KBO的碰撞粉碎。最近的工作强调了具有低速度色散的小的、碰撞的、原始的行星体如何允许大约5个海王星质量的寡头在15-25AU的距离内快速组装。我们探讨了这样一幅图景的后果。我们提出，其轨道与柯伊伯带相交的海王星质量行星有助于产生热的经典盘和散射带的高近日点成员。相比之下，在海王星的迁移过程中，通过扫荡长期共振来提高近日点可能会过于低效地填满这些储存库，因为考虑到大小约为100公里的天体中可能存在的原始质量是多么少。定量地讨论了这些以及跨海王星空间中的其他前沿问题。
The Edgeworth-Kuiper belt encodes the dynamical history of the outer solar system. Kuiper belt objects (KBOs) bear witness to coagulation physics, the evolution of planetary orbits, and external perturbations from the solar neighborhood. We critically review the present-day belt's observed properties and the theories designed to explain them. Theories are organized according to a possible time-line of events. In chronological order, epochs described include (1) coagulation of KBOs in a dynamically cold disk, (2) formation of binary KBOs by fragmentary collisions and gravitational captures, (3) stirring of KBOs by Neptune-mass planets (``oligarchs''), (4) eviction of excess oligarchs, (5) continued stirring of KBOs by remaining planets whose orbits circularize by dynamical friction, (6) planetary migration and capture of Resonant KBOs, (7) creation of the inner Oort cloud by passing stars in an open stellar cluster, and (8) collisional comminution of the smallest KBOs. Recent work underscores how small, collisional, primordial planetesimals having low velocity dispersion permit the rapid assembly of ~5 Neptune-mass oligarchs at distances of 15-25 AU. We explore the consequences of such a picture. We propose that Neptune-mass planets whose orbits cross into the Kuiper belt for up to ~20 Myr help generate the high-perihelion members of the hot Classical disk and Scattered belt. By contrast, raising perihelia by sweeping secular resonances during Neptune's migration might fill these reservoirs too inefficiently when account is made of how little primordial mass might reside in bodies having sizes of order 100 km. These and other frontier issues in trans-Neptunian space are discussed quantitatively.