Turbulent thermal diffusion: a way to concentrate dust in protoplanetary discs
Abstract
Turbulence acting on mixes of gas and particles generally diffuses the latter evenly through the former. However, in the presence of background gas temperature gradients, a phenomenon known as turbulent thermal diffusion appears as a particle drift velocity (rather than a diffusive term). This process moves particles from hot regions to cold ones. We re-derive turbulent thermal diffusion using astrophysical language and demonstrate that it could play a major role in protoplanetary discs by concentrating particles by factors of tens. Such a concentration would set the stage for collective behaviour such as the streaming instability and hence planetesimal formation.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- March 2016
- DOI:
- 10.1093/mnras/stv2895
- arXiv:
- arXiv:1512.02538
- Bibcode:
- 2016MNRAS.456.3079H
- Keywords:
-
- hydrodynamics;
- turbulence;
- planets and satellites: atmospheres;
- planets and satellites: formation;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 11 pages, 1 figure, accepted for publication, MNRAS