论文标题
Uranian系统的动力历史
Dynamical History of the Uranian System
论文作者
论文摘要
我们在数值上模拟了天王星五个大卫星（Miranda，Ariel，Umbriel，Titania和Oberon）的过去潮汐演变。我们发现，任何两个卫星（Ariel-umbriel 5：3 MMR）之间的最新主要平均动力共振（MMR）对整个系统产生了很大的影响。我们的结果表明，这种共鸣负责Miranda的当前4.3 $^{\ Circ} $（而不是先前建议的3：1 Miranda-Umbriel MMR），并且在这种共鸣期间，所有五个卫星都激动了他们的倾向。米兰达（Miranda）在阿里尔·乌姆布里尔（Ariel-Umbriel）5：3 mmr期间经历了明显的潮汐加热，因为阿里埃尔（Ariel）的世俗扰动激发了其偏心率。这种潮汐加热从米兰达轨道的收缩而不是阿里尔的向外进化中吸收能量，并且可以产生超过100 mw m $ $^{ - 2} $的热流，足以在米兰达生产幼冠。我们发现该MMR之后是一系列世俗共振，使卫星的偏心率和倾斜度重塑。我们还发现，Oberon旋转轴的进动与雨伞的轨道平面的进攻接近共鸣，并且在Ariel-Umbriel 5：3 mmr期间，这种自旋轨道共振很可能会激发。从MMR退出后，随后的Ariel-Umbriel世俗共振和Oberon-Umbriel Spin-Orbit共振可能能够解释当前Ariel和Umbriel的低倾向。米兰达（Miranda）表面特征的时代暂时表明Uranian Tidal $ Q = 15,000-20,000 $，这在将来的工作中可以进一步完善。
We numerically simulate the past tidal evolution of the five large moons of Uranus (Miranda, Ariel, Umbriel, Titania, and Oberon). We find that the most recent major mean-motion resonance (MMR) between any two moons, the Ariel-Umbriel 5:3 MMR, had a large effect on the whole system. Our results suggest that this resonance is responsible for the current 4.3$^{\circ}$ inclination of Miranda (instead of previously proposed 3:1 Miranda-Umbriel MMR), and that all five moons had their inclinations excited during this resonance. Miranda experienced significant tidal heating during the Ariel-Umbriel 5:3 MMR due to its eccentricity being excited by Ariel's secular perturbations. This tidal heating draws energy from shrinking of Miranda's orbit, rather than Ariel's outward evolution, and can generate heat flows in excess of 100 mW m$^{-2}$, sufficient to produce young coronae on Miranda. We find that this MMR was followed by a sequence of secular resonances, which reshuffled the moons' eccentricities and inclinations. We also find that the precession of Oberon's spin axis is close to a resonance with the precession of Umbriel's orbital plane, and that this spin-orbit resonance was likely excited during the Ariel-Umbriel 5:3 MMR. After the exit from the MMR, subsequent Ariel-Umbriel secular resonance and Oberon-Umbriel spin-orbit resonance may be able to explain the current low inclinations of Ariel and Umbriel. The age of Miranda's surface features tentatively suggests Uranian tidal $Q=15,000-20,000$, which can be further refined in future work.
