Growing dust grains in protoplanetary discs - III. vertical settling
Abstract
We aim to derive a simple analytic model to understand the essential properties of vertically settling growing dust grains in laminar protoplanetary discs. Separating the vertical dynamics from the motion in the disc mid-plane, we integrate the equations of motion for both a linear and an exponential grain growth rate. Numerical integrations are performed for more complex growth models. We find that the settling efficiency depends on the value of the dimensionless parameter γ , which characterizes the relative efficiency of grain growth with respect to the gas drag. Since γ is expected to be of the same order as the initial dust-to-gas ratio in the disc (≃10−2), grain growth enhances the energy dissipation of the dust particles and improves the settling efficiency in protoplanetary discs. This behaviour is mostly independent of the growth model considered as well as of the radial drift of the particles.
Citation
Laibe , G , Gonzalez , J F , Maddison , S T & Crespe , E 2014 , ' Growing dust grains in protoplanetary discs - III. vertical settling ' , Monthly Notices of the Royal Astronomical Society , vol. 437 , no. 4 , pp. 3055-3062 . https://doi.org/10.1093/mnras/stt1929
Publication
Monthly Notices of the Royal Astronomical Society
Status
Peer reviewed
ISSN
0035-8711Type
Journal article
Rights
© 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society
Description
TM acknowledges the support of a Swinburne Special Studies Programme. GL is grateful to the Australian Research Council for funding via Discovery project grant DP1094585, and acknowledges funding from the European Research Council for the FP7 ERC advanced grant project ECOGAL. JFG's research was conducted within the Lyon Institute of Origins under grant ANR-10-LABX-66.Collections
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.