论文标题
环形行星：迁移，陷入平均动作共振和弹射
Circumbinary planets: migration, trapping in mean-motion resonances, and ejection
论文作者
论文摘要
围绕二进制恒星发现的大多数行星系统位于其系统的Barycentre的大约三个半肌轴上，奇怪地接近低阶平均动作共振（MMR）。这些环形行星的形成机制尚未完全理解。由于与二进制的强烈相互作用，因此原位形成极具挑战性。一种可能的解释是，在它们形成之后，这些行星与周围的原始圆盘之间的相互作用导致它们以取决于盘子的性质和外部行星质量的速度迁移。尽管可以通过直接流体动力学模拟获得广泛的数据，但它们的计算成本仍然太高。另一方面，直接的N体模拟方法使我们能够以更低的成本对大量参数进行建模。我们使用类似于恒定的行星迁移以恒定速率模仿行星迁移的力的力分析了各种二元恒星周围的行星迁移。我们的目标是确定负责与内部二进制不同共振的行星弹射的主要参数。我们用类似Stokes的力进行了4200个N体模拟，并分析了它们的演变和结果，作为每个系统属性的函数。对于每个模拟系外行星，我们都应用了一种集合学习方法进行分类，以阐明检查参数与MMR捕获过程之间的关系。我们确定了不同N/1 mMR的捕获概率，4/1是捕获系外行星的最容易捕获的概率，其概率为37％，其次是MMR 5/1，$ \ sim $ \ sim $ 23％的概率。发现二进制的偏心率是确定每个电路系外行星的MMR捕获的最重要参数，其次是二进制的质量比和行星的初始偏心率。
Most of the planetary systems discovered around binary stars are located at approximately three semi-major axes from the barycentre of their system, curiously close to low-order mean-motion resonances (MMRs). The formation mechanism of these circumbinary planets is not yet fully understood. In situ formation is extremely challenging because of the strong interaction with the binary. One possible explanation is that, after their formation, the interactions between these planets and the surrounding protoplanetary disc cause them to migrate at velocities dependent on the nature of the disc and the mass of the exoplanet. Although extensive data can be obtained with direct hydrodynamical simulations, their computational cost remains too high. On the other hand, the direct n-body simulations approach allows us to model a large variety of parameters at much lower cost. We analyse the planetary migration around a wide variety of binary stars using Stokes-like forces that mimic planetary migration at a constant rate. Our goal is to identify the main parameters responsible for the ejection of planets at different resonances with the inner binary. We performed 4200 n-body simulations with Stokes-like forces and analysed their evolution and outcome as a function of the properties of each system. For each simulated exoplanet, we applied an ensemble learning method for classification in order to clarify the relationship between the inspected parameters and the process of MMR capture. We identify the capture probability for different N/1 MMRs, 4/1 being the most prone to capture exoplanets, with 37% probability, followed by MMR 5/1 with $\sim$ 23% of probability. The eccentricity of the binary is found to be the most important parameter in determining the MMR capture of each circumbinary exoplanet, followed by the mass ratio of the binary and the initial eccentricity of the planet.
