Giant-planet Influence on the Collective Gravity of a Primordial Scattered Disk
Giant-planet Influence on the Collective Gravity of a Primordial Scattered Disk
复制标题
巨行星对原始分散盘集体引力的影响
DOI：
10.3847/1538-3881/ab962f
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
A. Madigan
中科院分区：
文献类型：
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作者：
A. Zderic;A. Madigan
近开普勒轨道上的高偏心率、低质量天体的轴对称圆盘对于平面外屈曲是不稳定的。这种“倾角不稳定性”使轨道倾角呈指数级增长，增加近日点距离，并在近日点的角角中聚集。在这里，我们研究了一个巨大的原始分散盘的不稳定性，包括巨行星的轨道平均引力影响。我们表明，除非原始质量≥20 地球质量，否则由巨行星引起的近轴差进动将抑制倾角不稳定性。我们还表明，不稳定性会在数百个天文单位的半长轴处产生“近日点间隙”，因为残余群体的轨道更有可能具有比中间值更大的近日点距离（ ）。
Axisymmetric disks of high-eccentricity, low-mass bodies on near-Keplerian orbits are unstable to an out-of-plane buckling. This “inclination instability” exponentially grows the orbital inclinations, raises perihelion distances, and clusters in the argument of perihelion. Here we examine the instability in a massive primordial scattered disk including the orbit-averaged gravitational influence of the giant planets. We show that differential apsidal precession induced by the giant planets will suppress the inclination instability unless the primordial mass is ≳20 Earth masses. We also show that the instability should produce a “perihelion gap” at semimajor axes of hundreds of astronomical units, as the orbits of the remnant population are more likely to have extremely large perihelion distances ( ) than intermediate values.