The radial density profile of Saturn's A ring.

In this work, we model the radial density profile of the outer A ring of Saturn observed with Cassini cameras (Tiscareno & Harris 2018): An axisymmetric diffusion model has been developed, accounting for the outward viscous flow of the ring material, and the counteracting inward drift caused by resonances of the planet's large outer moons. It has been generally accepted that the 7:6 resonance of Janus alone confines the outer A ring which, however, was disproved by Tajeddine et al. (2017). We show that the step-like density profile of the outer A ring is predominantly defined by the discrete first-order resonances of Janus, the 5:3 second-order resonance of Mimas, and the overlapping resonances of Prometheus and Pandora.