2006/11/27 by Richard D. Alexander, R. D. Alexander, Philip J. Armitage +1 · 2 citations
Chemistry · Physics and Astronomy · #Astrophysics and Star Formation Studies #Molecular Spectroscopy and Structure #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2006.11341.x
published as Mon.Not.Roy.Astron.Soc.375:500-512,2007 · 13 pages, 5 figures. Accepted for publication in MNRAS
arxiv created 2006/11/27 · openalex publication_date 2007/01/18 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
We consider the dynamics of dust and gas during the clearing of protoplanetary discs. We work within the context of a photoevaporation/viscous model for the evolution of the gas disc, and use a two-fluid model to study the dynamics of dust grains as the gas disc is cleared. Small (≲10 μm) grains remain well coupled to the gas, but larger (∼1 mm) grains are subject to inward migration from large radii (∼50 au), suggesting that the time-scale for grain growth in the outer disc is ∼104–105 yr. We describe in detail the observable appearance of discs during clearing, and find that pressure gradients in the gas disc result in a strong enhancement of the local dust-to-gas ratio in a ring near to the inner disc edge. Lastly, we consider a simple model of the disc–planet interaction, and suggest that observations of disc masses and accretion rates provide a straightforward means of discriminating between different models of disc clearing.