Three Dynamical Evolution Regimes for Coupled Ring-Satellite Systems and Implications for the Formation of the Uranian Satellite Miranda

<p>In coupled ring-satellite systems, satellites exchange angular momentum with both the primary through tides and with the ring through Lindblad torques, and may exchange material with the ring through accretion and tidal disruption.  Here we show that these coupled ring-satellite systems fall into three distinct dynamical regimes, which we refer to as "Boomerang,'' "Non-Boomerang,'' and "Torque-Dependent.''  These regimes are determined by the relative locations of the Fluid Roche Limit, the synchronous orbit, and the location of the maximum orbit that Lindblad torques can perturb a satellite.  Satellites that accrete from rings in the Boomerang regime remain interior to the synchronous orbit, and may be driven back toward the primary by tides.  Satellites that accrete from rings in the Non-Boomerang regime form exterior to the synchronous orbit, and are always driven away from the primary.  Satellites that accrete from rings in the Torque-Dependent regime may exhibit either Boomerang or Non-Boomerang behavior, depending on ring and satellite masses.  We consider both known and hypothesized ring/satellite systems in the solar system, and identify which of these three regimes they fall into.  We determine that Uranus exists within the Torque-Dependent regime.  Using the RING-MOONS code, which models the dynamical evolution of coupled ring-satellite systems, we show that the Uranian satellite Miranda may have accreted from a massive ancient Roche-interior ring and followed a Non-Boomerang-like dynamical path to its present orbit beyond the synchronous orbit, while satellites that accreted after Miranda followed Boomerang-like evolution paths and remained interior to the synchronous orbit.</p>

<p>This publication includes data to reproduce figures as well as the version of RING-MOONS used to produce all data.</p>