Empty gaps? Depleting annular regions in debris discs by secular resonance with a two-planet system
Empty gaps? Depleting annular regions in debris discs by secular resonance with a two-planet system
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DOI：
10.1093/mnras/sty1678
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发表时间：
2018-06
影响因子：
4.8
通讯作者：
B. Yelverton;G. Kennedy
中科院分区：
文献类型：
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作者：
B. Yelverton;G. Kennedy
我们调查长期的时间尺度上的径向扩展的碎片盘的影响下，系统的两个共面行星内部的磁盘，显示长期的共振系统可以产生一个耗尽区的光盘通过激发的偏心率的星子。利用拉普拉斯-拉格朗日理论，我们考虑了两个外部长期共振位置，时间尺度和宽度如何依赖于行星的质量，半长轴和偏心率。特别是，我们发现，除非共振是非常接近彼此，其中之一是非常狭窄的，因此不重要的确定可观察到的结构的光盘。我们将这些考虑应用于HD 107146的碎片盘，确定一个可能的未观测到的双行星系统的参数组合，该系统可以适当地配置长期共振，以再现在盘中观察到的耗尽。通过对这些系统进行N体模拟，我们发现在理论长期共振位置附近，微行星的偏心率确实变大了。对N体输出进行后处理，以设置盘的初始表面密度分布，并包括碰撞耗尽的可能影响。我们发现，这是可能的，以获得一个双环盘在这些模拟，但不是一个轴对称的，与内环有一个偏移量的大小取决于偏心的行星，和外环显示螺旋结构。
We investigate the evolution on secular time-scales of a radially extended debris disc under the influence of a system of two coplanar planets interior to the disc, showing that the secular resonances of the system can produce a depleted region in the disc by exciting the eccentricities of planetesimals. Using Laplace-Lagrange theory, we consider how the two exterior secular resonance locations, time-scales and widths depend on the masses, semi-major axes and eccentricities of the planets. In particular, we find that unless the resonances are very close to each other, one of them is very narrow and therefore unimportant for determining the observable structure of the disc. We apply these considerations to the debris disc of HD 107146, identifying combinations of the parameters of a possible unobserved two-planet system that could configure the secular resonances appropriately to reproduce the depletion observed in the disc. By performing N-body simulations of such systems, we find that planetesimal eccentricities do indeed become large near the theoretical secular resonance locations. The N-body output is post-processed to set the initial surface density profile of the disc, and to include the possible effects of collisional depletion. We find that it is possible to obtain a double-ringed disc in these simulations but not an axisymmetric one, with the inner ring having an offset whose magnitude depends on the eccentricities of the planets, and the outer ring showing spiral structure.