Numerical Simulations of Saturn's B Ring: Granular Friction as a Mediator between Self-Gravity and Viscous Overstability

Abstract

We study the B ring's complex optical depth structure. The source of this structure may be the complex dynamics of the Keplerian shear and the self-gravity of the ring particles. The outcome of these dynamic effects depends sensitively on the collisional and physical properties of the particles. Two mechanisms can emerge that dominate the macroscopic physical structure of the ring: self-gravity wakes and viscous overstability. Here we study the interplay between these two mechanisms by using our recently developed particle collision method that allows us to better model the inter-particle contact physics. We find that for a constant ring surface density and particle internal density, particles with rough surfaces tend to produce axisymmetric ring features associated with the viscous overstability, while particles with smoother surfaces produce self-gravity wakes.

arXiv comment10 pages, 7 figures, Accepted for publication to the Astrophysical Journal

References in corpus (6)

• On the origin of irregular structure in Saturn's rings
• Numerical simulations of granular dynamics. I. Hard-sphere discrete element method and tests
• The B-ring's surface mass density from hidden density waves: Less than meets the eye?
• Low-speed Impact Simulations into Regolith in Support of Asteroid Sampling Mechanism Design I.: Comparison with 1-g Experiments
• Large-scale N-body simulations of the viscous overstability in Saturn's rings
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• Particle Number Dependence of The $N$-Body Simulations of Moon Formation
• Density Waves and the Viscous Overstability in Saturn's Rings
• Viscous Overstability in Saturn's Rings: Influence of Collective Self-gravity
• Rings of non-spherical, axisymmetric bodies
• Filament formation due to diffusive instabilities in dusty protoplanetary disks
• Hydrodynamics of granular gases of inelastic and rough hard disks or spheres. II. Stability analysis
• Thermal hysteresis and front propagation in dense planetary rings