Investigating the properties planetesimal systems with multiple members formed from gravitational collapse

Planetesimals are gravitationally bound objects that form in protoplanetary disks through accretion of dust and particles. They are an important critical phase in the formation of the planets, however their formation from a gravitationally collapsing cloud of small pebbles remains mysterious. In particular, simulated collapsed planetesimal systems typically contain excess angular momentum. Simulations show the formation of binary systems and their similarity to observed Kuiper Belt binaries, however these same simulations also show the formation of collapsed systems with three or more members.

For the purposes of this research project, we use the PKDGRAV N-body integrator and its Soft-sphere Discrete Element Method (SSDEM; Schwartz et al. 2012) method to understand how to identify and isolate planetesimals that contain multiple bound planetesimals in their system/in orbit around them. We precisely identify and characterize these multibody systems. Then we use a modified version of the General Use Binary Simulator (GUBAS; Davis & Scheeres, 2020) to study the long-term dynamical evolution of these multi-body systems. In particular, we examine the stability of these systems over the age of the Solar System.