Edge modes in self-gravitating disc-planet interactions Edge modes
Edge modes in self-gravitating disc-planet interactions Edge modes
复制标题
自引力圆盘-行星相互作用中的边缘模式 边缘模式
DOI：
10.1111/j.1365-2966.2011.18797.x
复制
发表时间：
2011
影响因子：
4.8
通讯作者：
Lin M
中科院分区：
文献类型：
--
作者：
Lin M
我们研究了一个巨大的行星在自引力原行星盘打开的间隙的稳定性。我们发现一个线性的不稳定性与自重力的光盘和当地涡度最大值与间隙边缘相吻合。对于我们的模型，这些边缘模式发展并延伸到土星质量行星的轨道半径的两倍，总质量为Md <$0.06M *，其中M * 是中心恒星质量，对应于ToomreQ <$1.5，是行星轨道半径的两倍。圆盘模型，虽然很大，但在没有行星的情况下是稳定的。与先前研究的局部涡形成不稳定性与间隙边缘弱或非自引力盘低粘度，边缘模式，我们认为是全球性的，只存在于足够大的磁盘，但典型的粘度值通过原行星盘。它示出通过分析建模和线性计算，边缘模式可以被解释为一个本地化的干扰与间隙边缘诱导活动在扩展光盘，通过发射的密度波激发通过引力位扰动在Lindblad共振。我们还进行流体动力学模拟，以调查在线性和非线性制度的圆盘行星系统的边缘模式的演变。发展不稳定模式的形式和增长率被发现是符合线性理论。他们的粘度和重力软化的依赖性也进行了探讨。我们还进行了第一次研究的边缘模式对盘行星扭矩和行星的轨道迁移的影响。我们发现，如果边缘模式发展，那么行星上的平均扭矩随着圆盘质量的增加而变得更加积极。在允许行星迁移的模拟中，虽然可以看到快速的III型迁移，这与非自引力盘中看到的相似，但我们发现行星可能与边缘模式相关的螺旋臂相互作用，这可能导致行星向外散射。因此，轨道迁移很可能是复杂的和非单调的大规模磁盘的类型，我们考虑。
We study the stability of gaps opened by a giant planet in a self-gravitating protoplanetary disc. We find a linear instability associated with both the self-gravity of the disc and local vortensity maxima which coincide with gap edges. For our models, these edge modes develop and extend to twice the orbital radius of a Saturn mass planet in discs with total massesMd≳ 0.06M*, whereM*is the central stellar mass, corresponding to a ToomreQ≲ 1.5 at twice the planet’s orbital radius. The disc models, although massive, are such that they are stable in the absence of the planet. Unlike the previously studied local vortex forming instabilities associated with gap edges in weakly or non-self-gravitating discs with low viscosity, the edge modes we consider are global and exist only in sufficiently massive discs, but for the typical viscosity values adopted for protoplanetary discs. It is shown through analytic modelling and linear calculations that edge modes may be interpreted as a localized disturbance associated with a gap edge inducing activity in the extended disc, through the launching of density waves excited through gravitational potential perturbation at Lindblad resonances. We also perform hydrodynamic simulations in order to investigate the evolution of edge modes in the linear and non-linear regimes in disc–planet systems. The form and growth rates of developing unstable modes are found to be consistent with linear theory. Their dependence on viscosity and gravitational softening is also explored. We also performed a first study of the effect of edge modes on disc–planet torques and the orbital migration of the planet. We found that if edge modes develop, then the average torque on the planet becomes more positive with increasing disc mass. In simulations where the planet was allowed to migrate, although a fast type III migration could be seen that was similar to that seen in non-self-gravitating discs, we found that it was possible for the planet to interact gravitationally with the spiral arms associated with an edge mode and that this could result in the planet being scattered outwards. Thus orbital migration is likely to be complex and non-monotonic in massive discs of the type we consider.