论文标题
在存在巨型行星II的情况下，行星动力学II：依赖行星质量和偏心率
Planetesimal Dynamics in the Presence of a Giant Planet II: Dependence on Planet Mass and Eccentricity
论文作者
论文摘要
在原星盘中存在一个早期形成的巨型行星，对其他行星胚胎的生长产生了不同的影响。地球上的重力扰动可以增加平均运动共振下行星可能的相对速度至非常高的值，并阻碍这些位置的吸积。但是，气体阻力还可以使某些磁盘位置相等大小的行星的轨道围绕轨道上心对齐，并使它们动态安静且“吸收友好型”位置，以适合类似尺寸的行星。在上一篇论文之后，我们研究了类似木星的行星对外部行星磁盘的影响，我们通过改变行星参数来将发现概括为极性行星系统。特别是，我们专注于行星相对速度对现有行星质量和偏心的依赖性。我们发现，相同的质量颗粒的速度分散会随着行星质量的增加而单调增加。同时，随着行星质量的增加，不同质量行星之间的相对速度对其质量比的依赖性变得较弱。尽管相对速度通常随着行星偏心率的增加而增加，但较小的质量颗粒的速度分散（$ m \ syssim 10^{18}〜\ rm {g} $）几乎与星球偏心率无关，因为它们的强耦合到气体上。我们发现，当行星尺寸降低时，在更广泛的参数（行星质量/偏心率，行星质量比）方面达到了侵蚀极限。我们的结果可以为土星核心的形成以及一些具有多个冷巨星的系外行星系统的建筑提供一些线索。
The presence of an early-formed giant planet in the protoplanetary disk has mixed influence on the growth of other planetary embryos. Gravitational perturbation from the planet can increase the relative velocities of planetesimals at the mean motion resonances to very high values and impede accretion at those locations. However, gas drag can also align the orbital pericenters of equal-size planetesimals in certain disk locations and make them dynamically quiet and "accretion-friendly" locations for planetesimals of similar sizes. Following the previous paper, where we investigated the effect of a Jupiter-like planet on an external planetesimal disk, we generalize our findings to extrasolar planetary systems by varying the planet parameters. In particular, we focus on the dependence of the planetesimal relative velocities on the mass and eccentricity of the existing planet. We found that the velocity dispersion of identical-mass particles increases monotonically with increasing planet mass. Meanwhile, the dependence of the relative velocity between different-mass planetesimals on their mass ratio becomes weaker as the planet mass increases. While the relative velocities generally increases with increasing planet eccentricity, the velocity dispersion of smaller-mass particles ($m \lesssim 10^{18}~\rm{g}$) is almost independent of planet eccentricity owing to their strong coupling to gas. We find that the erosion limits are met for a wider range of parameters (planet mass/eccentricity, planetesimal mass ratio) when the planetesimal size decreases. Our results could provide some clues for the formation of Saturn's core as well as the architecture of some exoplanetary systems with multiple cold giant planets.
