论文标题
Megasim：地球特洛伊小行星的寿命和共鸣 - 原始ETA的死亡？
MEGASIM: Lifetimes and Resonances of Earth Trojan Asteroids -- The Death of Primordial ETAs?
论文作者
论文摘要
我们介绍了Megasim数据集中地球特洛伊特型小行星（ETA）的生命和共振（Yeager＆Golovich 2022）中的分析。木马小行星与一个行星相连，但仍与拉格朗日点束缚，L4（60°领导行星）或L5（60°尾巴）。在圆形三体近似中，木马小行星的稳定性取决于宿主行星质量和中央质量的比率。对于内部行星，稳定性的范围变得越来越小，因此来自行星的扰动使原始的木马很少见。迄今为止，只有两个ETA（2010 TK7和2020 XL5），几个火星特洛伊木马和一个金星特洛伊木马。已知内部系统木马的估计寿命不到一百万年，这表明他们是闯入者，而不是稳定且持久的人群的成员。迄今为止，我们能够在广泛的初始化参数空间中跟踪其生存率。我们发现，随着时间的推移，ETA的剩余部分与拉伸的指数函数非常吻合，当超出模拟超出我们的模拟时，运行时间将零ETA预测为2.33 Gyr。我们还显示了ETA弹出与Milankovitch循环周期之间的相关性。尽管地球的轨道动力学占据了ETA的不稳定性，但我们提供了证据表明，ETA弹出与许多行星（如果不是全部行星）的轨道元素变化中发现的共振相关。
We present an analysis of lifetimes and resonances of Earth Trojan Asteroids (ETAs) in the MEGASIM data set (Yeager & Golovich 2022). Trojan asteroids co-orbit the Sun with a planet but remain bound to the Lagrange points, L4 (60° leading the planet) or L5 (60° trailing). In the circular three-body approximation, the stability of a Trojan asteroid depends on the ratio of the host planet mass and the central mass. For the inner planets, the range of stability becomes increasingly small, so perturbations from the planets have made primordial Trojans rare. To date there have been just two ETAs (2010 TK7 and 2020 XL5), several Mars Trojans, and a Venus Trojan discovered. The estimated lifetimes of the known inner system Trojans are less than a million years, suggesting they are interlopers rather than members of a stable and long-lasting population. With the largest ETA n-body simulation to date, we are able to track their survival across a wide initialized parameter space. We find the remaining fraction of ETAs over time is well fit with a stretched exponential function that when extrapolated beyond our simulation run time predicts zero ETAs by 2.33 Gyr. We also show correlations between ETA ejections and the periods of the Milankovitch cycles. Though Earth's orbital dynamics dominate the instabilities of ETAs, we provide evidence that ETA ejections are linked to resonances found in the variation of the orbital elements of many, if not all of the planets.
