Dust concentration and chondrule formation

TL;DR

This paper discusses the conflicting predictions of dust concentration levels in chondrule formation regions, highlighting the difficulty in achieving high dust densities in models and suggesting a need to reconsider concentration requirements.

Contribution

It analyzes the discrepancy between meteoritical and astrophysical models regarding dust concentration factors in chondrule formation, emphasizing the need for revised theories.

Findings

Models struggle to produce high dust concentration factors for chondrule precursors.

Significant discrepancies exist between meteoritical evidence and disk dynamics models.

Reconsideration of concentration factor requirements is recommended.

Abstract

Meteoritical and astrophysical models of planet formation make contradictory predictions for dust concentration factors in chondrule forming regions of the solar nebula. Meteoritical and cosmochemical models strongly suggest that chondrules, a key component of the meteoritical record, formed in regions with solids-to-gas mass ratios orders of magnitude above background. However, models of dust grain dynamics in protoplanetary disks struggle to surpass factors of a few outside of very brief windows in the lifetime of the dust grains. Worse, those models do not predict significant concentration factors for dust grains the size of chondrule precursors. We briefly develop the difficulty in concentrating dust particles in the context of nebular chondrule formation and show that the disagreement is sufficiently stark that cosmochemists should explore ideas that might revise the concentration factor requirements downwards.