We investigate the origins of Kepler-419, a peculiar system hosting two nearly coplanar and highly eccentric gas giants with apsidal orientations librating around anti-alignment, and use this system to place constraints on the properties of their birth protoplanetary disk. We follow the proposal by Petrovich, Wu, & Ali-Dib (2019) that these planets have been placed on these orbits as a natural result of the precessional effects of a dissipating massive disk and extend it by using direct N-body simulations and models for the evolution of the gas disks, including photoevaporation. Based on a parameter space exploration, we find that in order to reproduce the system the initial disk mass had to be at least 95 M_Jup and dissipate on a timescale of at least 10^4 yr. This mass is consistent with the upper end of the observed disk masses distribution, and the dissipation timescale is consistent with photoevaporation models. We study the properties of such disks using simplified 1D thin disk models and show that they are gravitationally stable, indicating that the two planets must have formed via core accretion and thus prone to disk migration. We hence finally investigate the sensitivity of this mechanism to the outer planet's semi major axis, and find that the nearby 7:1, 8:1, and 9:1 mean-motion resonances can completely quench this mechanism, while even higher order resonances can also significantly affect the system. Assuming the two planets avoid these high order resonances and/or close encounters, the dynamics seems to be rather insensitive to planet c semi major axis, and thus orbital migration driven by the disk.

中文翻译：

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用系外行星动力学约束原行星盘：以 Kepler-419 为例

我们调查了 Kepler-419 的起源，这是一个奇特的系统，拥有两个几乎共面且高度偏心的气态巨行星，它们的顶点方向在反对齐周围摇摆，并使用该系统对其诞生的原行星盘的特性进行限制。我们遵循 Petrovich、Wu 和 Ali-Dib (2019) 的建议，即这些行星被放置在这些轨道上是消散的巨大圆盘的岁差效应的自然结果，并通过使用直接 N 体模拟和模型对其进行扩展用于气体盘的演化，包括光蒸发。基于参数空间探索，我们发现为了重现系统，初始磁盘质量必须至少为 95 M_Jup，并且在至少 10^4 年的时间尺度上消散。这个质量与观察到的磁盘质量分布的上端一致，耗散时间尺度与光蒸发模型一致。我们使用简化的一维薄盘模型研究了这些盘的特性，并表明它们在重力上是稳定的，这表明这两颗行星一定是通过核心吸积形成的，因此容易发生盘迁移。因此，我们最终研究了这种机制对外行星半长轴的敏感性，发现附近的 7:1、8:1 和 9:1 平均运动共振可以完全抑制这种机制，而更高阶的共振也可以对系统也有很大影响。假设两颗行星避免了这些高阶共振和/或近距离接触，动力学似乎对行星 c 半长轴相当不敏感，因此由圆盘驱动的轨道迁移。