SECULAR BEHAVIOR OF EXOPLANETS: SELF-CONSISTENCY AND COMPARISONS WITH THE PLANET–PLANET SCATTERING HYPOTHESIS
SECULAR BEHAVIOR OF EXOPLANETS: SELF-CONSISTENCY AND COMPARISONS WITH THE PLANET–PLANET SCATTERING HYPOTHESIS
复制标题
系外行星的长期行为：自洽性以及与行星-行星散射假说的比较
DOI：
10.1088/0004-6256/146/3/63
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
N. Gorelick
中科院分区：
文献类型：
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作者：
Miles L Timpe;R. Barnes;R. Kopparapu;S. Raymond;Richard Greenberg;N. Gorelick
如果系外行星之间发生相互引力散射，那么它可能会产生独特的轨道特性。例如，如果行星-行星散射迅速地抛出前第三颗行星，使一颗行星在偏心轨道上，另一颗在圆形轨道上，那么位于近地点的环流和天平动之间边界附近的双行星系统可能会产生。我们首先通过将样本大小增加一倍并包括观测不确定性来改进先前的工作，该工作检查了已知多行星系统的拱点行为。这一分析恢复了以前的结果，表明许多系统位于天平动和环流之间的拱线边界上。然后，我们进行了超过12，000个假设的三体系统的三维N体模拟，这些三体系统是不稳定的，但在弹射后稳定为两体系统。使用这些合成的两个行星系统，我们测试行星-行星散射假设，通过比较他们的拱点行为，在一个范围内的视角，观察到的系统，发现它们是统计上一致的，无论观察到的系统的多重性。最后，我们将联合收割机的结果与以前的研究相结合，表明从采样的情况下，最有可能的行星质量函数在行星-行星散射之前遵循指数为-1.1的幂律。我们发现，这个预散射质量函数预测了一个相互倾斜的频率分布，它遵循一个指数函数，指数在-0.06和-0.1之间。
If mutual gravitational scattering among exoplanets occurs, then it may produce unique orbital properties. For example, two-planet systems that lie near the boundary between circulation and libration of their periapses could result if planet–planet scattering ejected a former third planet quickly, leaving one planet on an eccentric orbit and the other on a circular orbit. We first improve upon previous work that examined the apsidal behavior of known multiplanet systems by doubling the sample size and including observational uncertainties. This analysis recovers previous results that demonstrated that many systems lay on the apsidal boundary between libration and circulation. We then performed over 12,000 three-dimensional N-body simulations of hypothetical three-body systems that are unstable, but stabilize to two-body systems after an ejection. Using these synthetic two-planet systems, we test the planet–planet scattering hypothesis by comparing their apsidal behavior, over a range of viewing angles, to that of the observed systems and find that they are statistically consistent regardless of the multiplicity of the observed systems. Finally, we combine our results with previous studies to show that, from the sampled cases, the most likely planetary mass function prior to planet–planet scattering follows a power law with index −1.1. We find that this pre-scattering mass function predicts a mutual inclination frequency distribution that follows an exponential function with an index between −0.06 and −0.1.