Dust dynamics during protoplanetary disc clearing

R. D. Alexander; P. J. Armitage

doi:10.1111/j.1365-2966.2006.11341.x

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arXiv · astro-ph/0611821

Dust dynamics during protoplanetary disc clearing

R. D. Alexander·P. J. Armitage

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Abstract

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 (<~10um) grains remain well-coupled to the gas, but larger (~1mm) grains are subject to inward migration from large radii (~50AU), suggesting that the time-scale for grain growth in the outer disc is ~10^4-10^5yr. 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.

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R. D. Alexander, P. J. Armitage. 2006-11-27. Dust dynamics during protoplanetary disc clearing. https://doi.org/10.1111/j.1365-2966.2006.11341.x

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