Presentation #631.01 in the session Other - Theory.
Small satellites embedded in Saturn’s ring - Daphnis and Pan - open a clear gap. Observations by the Voyager and Cassini spacecrafts have revealed various striking features of the gap structure, such as the density waves, sharp edge, and vertical structure. Since the Cassini observation, these features have been investigated separately with different theoretical approaches: the streamline models, 1D diffusion models, and local N-body simulation. To treat these features in a single simulation, we perform a high-resolution (N~106-107) global full N-body simulation of gap formation by an embedded satellite considering gravitational interactions and inelastic collisions among all ring particles and an embedded satellite. As a first attempt of our series of studies, we fix the satellite orbit in a Keplerian circular orbit to split the gap formation and the satellite migration. We find that striking gap features observed by Cassini - the density wave, sharp edge, and vertical structure - are reproduced simultaneously and consistently. Our results show that frequent inelastic collisions among ring particles damp their eccentricity and cause “negative diffusion”, which leads to the enhancement of the surface density at the gap edge, and its sharp edge are more pronounced. We also find that particles’ vertical splashing results from a collision in the density wavefront, which compresses the particle orbits and enhances the surface density. This mechanism forms a vertical mountain-like structure even in the case of the satellite in the non-inclined orbit.