Concentrating small particles in protoplanetary disks through the streaming instability

Research output: Contribution to journalArticle

Abstract

Laboratory experiments indicate that direct growth of silicate grains via mutual collisions can only produce particles up to roughly millimeters in size. On the other hand, recent simulations of the streaming instability have shown that mm/cm-sized particles require an excessively high metallicity for dense filaments to emerge. Using a numerical algorithm for stiff mutual drag force, we perform simulations of small particles with significantly higher resolutions and longer simulation times than in previous investigations. We find that particles of dimensionless stopping time τs = 10-2 and 10-3 - representing cm- and mm-sized particles interior of the water ice line - concentrate themselves via the streaming instability at a solid abundance of a few percent. We thus revise a previously published critical solid abundance curve for the regime of τs ≪ 1. The solid density in the concentrated regions reaches values higher than the Roche density, indicating that direct collapse of particles down to mm sizes into planetesimals is possible. Our results hence bridge the gap in particle size between direct dust growth limited by bouncing and the streaming instability.

Details

Authors
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Astronomy, Astrophysics and Cosmology

Keywords

  • Hydrodynamics, Instabilities, Methods: numerical, Minor planets, asteroids: general, Planets and satellites: formation, Protoplanetary disks
Original languageEnglish
Article numberA80
JournalAstronomy and Astrophysics
Volume606
StatePublished - 2017 Oct 1
Peer-reviewedYes