Collisional fragmentation and bulk composition tracking in REBOUND

Abstract

We present a fragmentation module and a composition tracking code for the $n$-body code REBOUND. Our fragmentation code utilises previous semi-analytic models and follows an implementation method similar to fragmentation for the $n$-body code MERCURY. In our $n$-body simulations with fragmentation, we decrease the collision and planet formation timescales by inflating the particle radii by an expansion factor $f$ and experiment with various values of $f$ to understand how expansion factors affect the collision history and final planetary system. As the expansion factor increases, so do the rate of mergers which produces planetary systems with more planets and planets at larger orbits. Additionally, we present a composition tracking code which follows the compositional change of homogeneous bodies as a function of mass exchange and use it to study how fragmentation and the use of an expansion factor affects volatile delivery to the inner terrestrial disc. We find that fragmentation enhances radial mixing relative to perfect merging and that on average, as $f$ increases so does the average water mass fraction of the planets. Radial mixing decreases with increasing $f$ as collisions happen early on, before the bodies have time to grow to excited orbits and move away from their original location

Accepted for publication in MNRAS. 12 pages, 7 figures, and 5 tables

References in corpus (8)

• The origins and concentrations of water, carbon, nitrogen and noble gases on Earth
• Hybrid Symplectic Integrators for Planetary Dynamics
• The structure of terrestrial bodies: Impact heating, corotation limits and synestias
• Chemistry in an Evolving Protoplanetary Disk: Effects on Terrestrial Planet Composition
• A Collisional Origin to Earth's Non-chondritic Composition?
• Realistic On-the-fly Outcomes of Planetary Collisions II: Bringing Machine Learning to N-body Simulations
• Realistic collisional water transport during terrestrial planet formation: Self-consistent modeling by an N-body--SPH hybrid code
• Terrestrial planet formation in a circumbinary disc around a coplanar binary

Cited by in corpus (1)

• Misalignment of terrestrial circumbinary planets as an indicator of their formation mechanism