The physics of protoplanetesimal dust agglomerates. X. High-velocity collisions between small and large dust agglomerates as growth barrier

TL;DR

This study investigates high-velocity collisions between small and large dust agglomerates in protoplanetary disks, revealing erosion as a key growth barrier that influences dust size distribution.

Contribution

It provides experimental data and models showing how erosion limits dust growth, establishing a new understanding of dust evolution in protoplanetary disks.

Findings

Erosion dominates at high collision velocities, preventing growth beyond certain sizes.

A steady-state dust size distribution from micrometer to decimeter scales is established.

Collision thresholds depend on size and velocity, affecting planetesimal formation.

Abstract

In a protoplanetary disk, dust aggregates in the $\mu$m to mm size range possess mean collision velocities of 10 to 60 ms$^{-1}$ with respect to dm- to m-size bodies. We performed laboratory collision experiments to explore this parameter regime and found a size- and velocity-dependent threshold between erosion and growth. By using a local Monte Carlo coagulation calculation and complementary a simple semi-analytical timescale approach, we show that erosion considerably limits particle growth in protoplanetary disks and leads to a steady-state dust-size distribution from $\mu$m to dm sized particles.