AI 中文总结
本研究通过混合方法模拟星团环境下行星系统演化，发现初始含各向同性恒星伴星的系统中，飞掠诱导的高偏心率迁移可解释M67热木星高发生率，其形成率较无飞掠情况提升约2倍。
AI 中文摘要
几乎没有行星系统是孤立形成的，相反，它们诞生环境中的相互作用可能会塑造其结构或使其进入不稳定构型。本研究探讨了致密星团中环境扰动触发动力学不稳定性进而导致热木星形成的作用，重点关注疏散星团M67中热木星的高发生率是否可通过飞掠诱导的高偏心率迁移来解释。我们开发了一种混合方法，结合解析与数值方法来模拟经过恒星的外部扰动下行星系统的长期演化与潮汐演化。我们在类似M67的星团中，对单行星、双行星、行星-恒星伴星系统各演化10000个实现，时长约4 Gyr，并将结果统计与无飞掠的对照样本对比。在单行星和双行星系统中，飞掠诱导的热木星形成率可忽略不计；但在初始具有各向同性取向恒星伴星的系统中，星团环境使热木星形成率提升约2倍，同时经历潮汐瓦解的行星比率增加约3倍。基于观测驱动的原始星群估计，若类太阳恒星的原始宽双星占比接近~50%、双星驱动的高偏心率迁移是主导形成路径，且相当比例的潮汐瓦解系统通过部分质量损失存活为热木星，我们的热木星产出与场星及M67的发生率均一致。
英文摘要
Few planetary systems form in isolation. Rather, interactions in their birth environments may sculpt their architectures or drive them into unstable configurations. Here we study the role of environmental perturbations in triggering dynamical instabilities leading to hot Jupiter formation in dense clusters, focusing on whether the elevated occurrence rate of hot Jupiters in the open cluster M67 can be explained through flyby-induced high-eccentricity migration. We develop a hybrid method for modelling the secular and tidal evolution of planetary systems under external perturbations by passing stars using a combination of analytic and numerical approaches. We evolve 10,000 realizations each of systems with either a single planet, two planets, or a planet and a stellar companion for $\sim$4 Gyr in an M67-like cluster, comparing outcome statistics against a control sample without flybys. In single- and two-planet systems, the rate of flyby-induced hot Jupiter formation is negligible. However, in systems with an initially isotropically oriented stellar companion, the cluster environment boosts hot Jupiter formation by a factor of $\sim$2, accompanied by a factor of $\sim$3 increase in the rate of planets undergoing tidal disruption. Based on observationally motivated estimates of primordial populations, our hot Jupiter yields are consistent with both field and M67 occurrence rates, provided the primordial wide binary fraction among solar-type stars is close to $\sim$50 per cent, binary-driven high-eccentricity migration is the dominant formation pathway, and a substantial fraction of tidally disrupted systems survive as hot Jupiters through partial mass loss.
Comments25 pages, 13 figures, accepted for publication in MNRAS
