Moonlets in planetaren Ringen: Implikationen für die Ringteilchendynamik?

Spahn和Sremcevic等人(2000年)对嵌入小卫星(小卫星)引起的卫星S环内螺旋桨结构的预测。(2002)和Seiçet al.(2005年)导致最近在土星S环中探测到小卫星(Tiscareno等人，2006年；Sremcevic等人，2007年；Tiscareno等人，2008年)。然而，螺旋桨结构的亮度与先前预测的特征有所偏离。对从N体模拟获得的粒子配置的初步光度研究表明，如果在扰动区域产生小的碎片颗粒，原则上可以理解螺旋桨图案的亮度(Sremcevic等人，2007年)。这种碎片以前停留在较大的环状颗粒表面，由于扰动环状区域的撞击速度增强，可以释放出来，这样就增加了观测到的螺旋桨特征的亮度。该项目的目的是计算由于摄动而引起的粘性和重力环状粒子系综的粒子尺寸分布的变化。随后将确定由此产生的光学厚度的修改，并将其与观测到的推进器相关联。通过这种方式，可以更好地理解环亮度中观察到的图案对质量密度中潜在扰动的依赖关系。这将反过来改善对嵌入的小卫星的质量、环粘度的约束，以及对环颗粒之间的粘合强度及其对环颗粒尺寸分布的重要性的估计。扰动环区域尺寸分布变化的模型也可以应用于其他环特征，如最外层A环的缺失环亮度不对称效应、强共振周围的亮度晕(例如Janus 5：4密度波，Nicholson等人)。(2008))和土星S F环上的临时团块和亮度爆发。

The prediction of propeller structures in Satum s rings caused by embedded small satellites (moonlets) by Spahn and Sremcevic (2000), Sremcevic et al. (2002) and Seiß et al. (2005) led to recent detections of moonlets in Saturn s rings (Tiscareno et al., 2006; Sremcevic et al., 2007; Tiscareno et al., 2008). The brightness of the propeller structures, however, deviated from the formerly predicted features. A preliminary photometric study of particle configurations obtained from N-body simulations demonstrated that the brightness of the propeller pattern can in principle be understood if small debris particles are produced in perturbed regions (Sremcevic et al., 2007). This debris, formerly resting on the surfaces of larger ring particles, can be released due to enhanced impact velocities in perturbed ring regions, in this way increasing the brightness of the observed propeller features. The aim of the project is to calculate the change of the particles size distribution of an ensemble of adhering and gravitating ring particles due to perturbations. The resulting modifications of the optical depth will then be determined and related to the observed propellers. In this way an improved understanding of the dependence of the observed pattern in the ring brightness on the underlying perturbation in the mass density can be obtained. This will in turn lead to improved constraints for the mass of the embedded moonlets, the ring viscosity as well as an estimate for the strength of the adhesion between the ring particles and its importance for the ring particle size distribution. A model for the change of the size distribution in perturbed ring regions could also be applied to other ring features as the missing ring brightness asymmetry effect in the outermost A ring, the brightness halos around strong resonances (e.g. Janus 5:4 density wave, Nicholson et al. (2008)) and the temporary clumps and brightness bursts in Saturn s F ring.