Composition Tracking for Collisions Between Differentiated Bodies in REBOUND

TL;DR

This paper introduces a new post-processing tool for N-body simulations that tracks compositional changes during planetary collisions, helping to understand the formation of iron-rich planets.

Contribution

The Differentiated Body Composition Tracker is a novel tool that integrates collisional data from REBOUND to analyze core and mantle material transfer during impacts.

Findings

The tool effectively models compositional transfer in simulated planetary collisions.

Enrichment of core material can lead to the formation of iron-rich planets.

Non-uniform initial core distributions influence final planetary compositions.

Abstract

Previous research suggests that impacts between planetary embryos and planetesimals during the late stages of planet formation can often determine the percentages of core and mantle material that compose the newly formed planets in a system. Previous studies have attempted to include the composition-changing effects of these collisions in N-body simulations of planet formation, often as post-processing codes. In this paper, we present the Differentiated Body Composition Tracker, a new post-processing tool that uses collisional data collected from the N-body integrator REBOUND to determine the amount of core and mantle material that is transferred between colliding objects and the resulting fragments during an impact. We demonstrate how this code works using the data from 50 REBOUND simulations of planet formation and explore how the parameters in the code affect the core mass fractions of the remaining objects from these simulations. We then investigate how non-uniform distributions of core material across an initial disc affect the final core mass fractions of planets. Under ideal conditions, we find that a combination of giant impacts and planetary embryos enriched in core material could create some of the iron-rich planets that have been discovered.