The Role of Early Giant-planet Instability in Terrestrial Planet Formation
The Role of Early Giant-planet Instability in Terrestrial Planet Formation
复制标题
早期巨行星不稳定性在类地行星形成中的作用
DOI：
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
R. Deienno
中科院分区：
文献类型：
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作者：
D. Nesvorný;F. Roig;R. Deienno
这些类地行星被认为是由数十颗月球大小的原行星与火星大小的原行星在原行星气盘扩散（t 0）后时间 t < 200 Myr 的剧烈碰撞形成的。太阳系巨行星在原行星盘阶段迅速形成，并在t 0 之后通过与外盘星子相互作用而径向迁移。人们认为，早期（t < 100 Myr）的动力学不稳定性是在木星与行星大小的天体发生引力相遇时发生的，木星向内跳跃约0.2-0.5天文单位，并降落在其当前的略微偏心的轨道上。在这里，我们研究巨行星的不稳定性如何影响类地行星的形成。我们研究了几种不稳定性情况，这些情况之前已被证明符合许多太阳系的限制。我们发现，与巨行星的共振有助于去除约 1.5 个天文单位附近可吸积的固体，从而阻碍火星的生长。然而，巨行星是否在 t 0 时被放置在当前轨道上，或者它们是否在我们的不稳定模型之一中实际演化，并不重要。结果几乎是一样的。金星和地球的紧密轨道间距在我们的模拟中很难重现，包括天体从 0.7-1 天文单位的狭窄环面生长的情况，因为原行星在吸积过程中往往呈放射状扩散。当假设从分散气体星云中出现的原行星具有（至少）火星的质量时，在窄环空模型中可以获得最佳结果。这表明类地原行星在太阳系最初~10 Myr期间发生了有效的吸积。
The terrestrial planets are believed to have formed by violent collisions of tens of lunar- to Mars-size protoplanets at time t < 200 Myr after the protoplanetary gas disk dispersal (t 0). The solar system giant planets rapidly formed during the protoplanetary disk stage and, after t 0, radially migrated by interacting with outer disk planetesimals. An early (t < 100 Myr) dynamical instability is thought to have occurred with Jupiter having gravitational encounters with a planetary-size body, jumping inward by ∼0.2–0.5 au, and landing on its current, mildly eccentric orbit. Here we investigate how the giant-planet instability affected the formation of the terrestrial planets. We study several instability cases that were previously shown to match many solar system constraints. We find that resonances with giant planets help to remove solids available for accretion near ∼1.5 au, thus stalling the growth of Mars. It does not matter, however, whether the giant planets are placed on their current orbits at t 0 or whether they realistically evolve in one of our instability models; the results are practically the same. The tight orbital spacing of Venus and Earth is difficult to reproduce in our simulations, including cases where bodies grow from a narrow annulus at 0.7–1 au, because protoplanets tend to spread radially during accretion. The best results are obtained in the narrow-annulus model when protoplanets emerging from the dispersing gas nebula are assumed to have (at least) the mass of Mars. This suggests efficient accretion of the terrestrial protoplanets during the first ∼10 Myr of the solar system.
使用 GPU 加速的胚胎形成：重新评估陆地吸积的初始条件
影响因子：
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作者：
Clement, Matthew S.;Kaib, Nathan A.;Chambers, John E.
通讯作者：
Chambers, John E.
影响因子：
4.9
作者：
Agnor, Craig B.;Lin, D. N. C.
通讯作者：
Lin, D. N. C.