SPH/N-body simulations of small (D = 10 km) asteroidal breakups and improved parametric relations for Monte-Carlo collisional models

TL;DR

This study uses SPH/N-body simulations to analyze small asteroid breakups, providing new parametric relations for fragment distributions and insights into velocity and angular distributions, improving Monte-Carlo collisional models.

Contribution

The paper introduces new parametric relations for fragment size and velocity distributions from small asteroid breakups, enhancing modeling accuracy.

Findings

Fragment distributions differ significantly from larger asteroid simulations.

New parametric relations for fragment sizes are derived.

Velocity and angular distributions of fragments are characterized.

Abstract

We report on our study of asteroidal breakups, i.e. fragmentations of targets, subsequent gravitational reaccumulation and formation of small asteroid families. We focused on parent bodies with diameters $D_{\rm pb} = 10$ km. Simulations were performed with a smoothed-particle hydrodynamics (SPH) code combined with an efficient N-body integrator. We assumed various projectile sizes, impact velocities and impact angles (125 runs in total). Resulting size-frequency distributions are significantly different from scaled-down simulations with $D_{\rm pb} = 100$ km targets (Durda et al., 2007). We derive new parametric relations describing fragment distributions, suitable for Monte-Carlo collisional models. We also characterize velocity fields and angular distributions of fragments, which can be used as initial conditions for N-body simulations of small asteroid families. Finally, we discuss a number of uncertainties related to SPH simulations.