The motion of chondrules and other particles in a protoplanetary disc with temperature fluctuations

TL;DR

This paper explores a novel photophoretic mechanism driven by temperature fluctuations within optically thick protoplanetary disks, affecting particle transport, size sorting, and dust evolution.

Contribution

It introduces a new model of photophoretic transport caused by internal disk temperature fluctuations, not stellar radiation, impacting early dust growth processes.

Findings

Explains size sorting and density enhancements in particles.

Predicts velocity fluctuations exceeding 100 m/s for mm-sized particles.

Suggests implications for dust evolution and aggregate growth.

Abstract

We consider the mechanism of photophoretic transport in protoplanetary disks that are optically thick to radiation. Here, photophoresis is not caused by the central star but by temperature fluctuations that subject suspended solid particles, including chondrules, to non-isotropic thermal radiation within the disk. These short-lived temperature fluctuations can explain time-of-flight size sorting and general number density enhancements. The same mechanism will also lead to velocity fluctuations of dust aggregates beyond $100\,\mathrm{m\,s^{-1}}$ for mm-sized particles in protoplanetary disks. Applying this in future research will change our understanding of the early phases of collisional dust evolution and aggregate growth as particles cross the bouncing barrier and as mass transfer rates are altered.