The Scattering Outcomes of Kepler Circumbinary Planets: Planet Mass Ratio
The Scattering Outcomes of Kepler Circumbinary Planets: Planet Mass Ratio
复制标题
开普勒环双星行星的散射结果：行星质量比
DOI：
10.3847/1538-3881/aa8c7c
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Ji Jianghui
中科院分区：
文献类型：
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作者：
Gong Yan-Xiang;Ji Jianghui
最近的研究表明，Kepler-34b和Kepler-413b的自由偏心率远大于它们的强迫偏心率，这意味着它们的形成可能发生了散射事件。观测到的开普勒-34b的轨道配置不能很好地再现在磁盘驱动的迁移模型，而两个行星散射的情况下可以发挥重要作用的塑造行星配置。这些研究表明，开普勒发现的环双星行星可能经历了散射过程。在这项工作中，我们广泛的调查散射的结果，环联行星的行星质量比的影响为重点。我们发现，行星质量比和行星的初始相对位置是影响幸存行星偏心率分布的两个重要参数。作为模型的应用，我们讨论了观测到的Kepler-34b和Kepler-413b的轨道构型。我们首先采用盘驱动模型的结果作为初始条件，然后模拟了发生在环双星行星演化后期的散射过程。我们表明，目前的轨道配置的开普勒-34 b和开普勒-413 b时，考虑两个不等质量的行星喷射模型可以很好地再现。我们的工作进一步表明，目前发现的一些环双星单行星系统可能是原始多行星系统的幸存者。后期发生的盘驱迁移和散射事件对最终系统的塑造起着不可替代的作用。
Recent studies reveal that the free eccentricities of Kepler-34b and Kepler-413b are much larger than their forced eccentricities, implying that scattering events may take place in their formation. The observed orbital configuration of Kepler-34b cannot be well reproduced in disk-driven migration models, whereas a two-planet scattering scenario can play a significant role of shaping the planetary configuration. These studies indicate that circumbinary planets discovered by Kepler may have experienced scattering process. In this work, we extensively investigate the scattering outcomes of circumbinary planets focusing on the effects of planet mass ratio. We find that the planetary mass ratio and the the initial relative locations of planets act as two important parameters that affect the eccentricity distribution of the surviving planets. As an application of our model, we discuss the observed orbital configurations of Kepler-34b and Kepler-413b. We first adopt the results from the disk-driven models as the initial conditions, then simulate the scattering process that occurs in the late evolution stage of circumbinary planets. We show that the present orbital configurations of Kepler-34b and Kepler-413b can be well reproduced when considering a two unequal-mass planet ejection model. Our work further suggests that some of the currently discovered circumbinary single-planet systems may be survivors of original multiple-planet systems. The disk-driven migration and scattering events occurring in the late stage both play an irreplaceable role in sculpting the final systems.