标题： 邻近卫星的平均运动共振：外行星J1407b环中观测到的间隙起源不太可能的原因 显示英文标题

标题： Mean Motion Resonances With Nearby Moons: An Unlikely Origin For The Gaps Observed In The Ring Around The Exoplanet J1407b

摘要： 利用数值模型，我们研究了是否土星外环J1407b系统的近邻卫星的平均运动共振（MMR）导致了观测到的宽0.0267天文单位、位于0.4天文单位处的间隙。仅发现一颗位于0.63天文单位（对应2:1 MMR）的卫星在不到100年的短时间内形成了一个位于0.4天文单位处的间隙。然而，一颗低质量卫星（0.08个地球质量）靠近时，导致外部环边缘在0.6天文单位处显著散射，并且在3:2 MMR（0.485天文单位）处形成额外的间隙，这与观测结果不符。进一步的模型中，卫星分别位于3:1、4:1、7:3和5:3 MMR时，在不到100年的短时间内未能在0.4天文单位处形成间隙，反而在3:2和2:1 MMR处形成了环上的间隙，最终在0.44-0.56天文单位径向位置形成间隙。此外，这些间隙需要超过J1407b围绕主星的一个轨道周期才能形成。鉴于J1407b处于高度偏心轨道，并被认为在远地点强烈扰动环系统，因此不太可能由于附近卫星的MMR而形成间隙，而不是嵌入式卫星。当加入相当于一个地球质量的适当总环质量时，观察到了对间隙形成过程的阻尼效应，从而增加了由于MMR而打开间隙所需的时间。因此，我们得出结论，0.4天文单位处观测到的间隙不太可能是由附近卫星的MMR引起的。 显示英文摘要

摘要： With the use of numerical models, we investigate whether Mean Motion Resonances (MMR) with nearby moons to the J1407b ring system were the cause of the observed 0.0267AU wide gap located at 0.4AU. Only one location of a moon at 0.63AU (corresponding to a 2:1 MMR) was found to form a gap at 0.4AU over short time periods of less than 100yr. However, the proximity of a low mass moon (0.08 Earth masses) caused significant scattering of the outer ring edge at 0.6AU, along with the formation of an additional gap at the 3:2 MMR (0.485 AU), which is not consistent with observations. Further models with moons located at MMR 3:1, 4:1, 7:3 and 5:3 failed to form gaps at 0.4AU for time periods less than 100yr. Instead, gaps were formed in the ring at 3:2 and 2:1 MMR which resulted in gaps at radial locations between 0.44-0.56AU. Additionally, gaps also take longer than one orbital period of J1407b about the primary to form. Given that J1407b is on a highly eccentric orbit and is thought to strongly perturb the ring at apocentre it appears unlikely that gaps form due to MMR with nearby moons as opposed to embedded moons. Including an appropriate total mass of the ring equal to Earth a dampening effect was witnessed on the gap formation process, causing an increase in the time required to open a gap due to MMR. Therefore, we conclude the observed gap at 0.4 AU is unlikely to be caused by MMR with nearby moons.