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 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 the 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 radially spread 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 Mars mass. This suggests efficient accretion of the terrestrial protoplanets during the first ~10 Myr of the solar system.

中文翻译：

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早期巨行星不稳定性在类地行星形成中的作用

据信，这些类地行星是在原行星气体盘扩散 (t_0) 之后的 t<200 Myr 时间由数十颗月球到火星大小的原行星剧烈碰撞而形成的。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。早期的（t<100 Myr）动力学不稳定被认为是在木星与行星大小的天体发生引力相遇时发生的，向内跳跃~0.2-0.5 au，并降落在其当前的、温和的偏心轨道上。在这里，我们研究了巨行星的不稳定性如何影响类地行星的形成。我们研究了之前显示出与许多太阳系约束相匹配的几种不稳定情况。我们发现与巨行星的共振有助于去除可在~1.5 au 附近吸积的固体，从而阻止火星的生长。然而，巨行星是否被放置在 t_0 时的当前轨道上，或者它们是否在我们的不稳定性模型之一中实际演化并不重要；结果几乎相同。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 au 的狭窄环带生长的情况，因为原行星在吸积过程中倾向于径向扩散。当假设从分散的气体星云中出现的原行星具有（至少）火星质量时，在窄环模型中获得了最好的结果。这表明在太阳系的第一个 ~10 Myr 期间，类地原行星的有效吸积。