论文标题
由气体磁盘扩散触发的早期太阳系不稳定
Early Solar System instability triggered by dispersal of the gaseous disk
论文作者
论文摘要
人们认为太阳系的轨道结构被巨型行星的动态不稳定雕刻而成。但是，尚未明确确定不稳定的触发因素和时机。流体动力学建模表明，虽然存在太阳的气态原动性磁盘，但巨型行星在一系列共振链中迁移到紧凑的轨道构型中。在这里，我们使用动力学模拟表明，巨型行星的不稳定性可能是由气体磁盘的扩散触发的。随着磁盘从内而外蒸发，其内部边缘依次横跨并动态扰动每个行星的轨道。相关的轨道转移引起了系统外部的动态压缩，最终触发了不稳定性。我们的模拟系统的最终轨道与太阳系的最终轨道相匹配，可与天体物理参数范围可行。因此，随着气态磁盘消散，受天文观测的限制是在太阳系诞生后的几到一千万年的，因此发生了巨大的行星不稳定。直到如此早期的巨型行星不稳定之后，陆地行星的形成才能完成。不断增长的陆地行星甚至可能是通过其扰动来雕刻的，从而解释了相对于地球的少量火星。
The Solar System's orbital structure is thought to have been sculpted by an episode of dynamical instability among the giant planets. However, the instability trigger and timing have not been clearly established. Hydrodynamical modeling has shown that while the Sun's gaseous protoplanetary disk was present the giant planets migrated into a compact orbital configuration in a chain of resonances. Here we use dynamical simulations to show that the giant planets' instability was likely triggered by the dispersal of the gaseous disk. As the disk evaporated from the inside-out, its inner edge swept successively across and dynamically perturbed each planet's orbit in turn. The associated orbital shift caused a dynamical compression of the exterior part of the system, ultimately triggering instability. The final orbits of our simulated systems match those of the Solar System for a viable range of astrophysical parameters. The giant planet instability therefore took place as the gaseous disk dissipated, constrained by astronomical observations to be a few to ten million years after the birth of the Solar System. Terrestrial planet formation would not complete until after such an early giant planet instability; the growing terrestrial planets may even have been sculpted by its perturbations, explaining the small mass of Mars relative to Earth.
