Accretion through the inner hole of transitional disks: what happens to the dust?

¹ Sterrenkundig Instituut “Anton Pannekoek”, Science Park 904, 1098 XH Amsterdam, The Netherlands
e-mail: dominik@uva.nl
² Afdeling Sterrenkunde, Radboud Universiteit Nijmegen, Postbus 9010, 6500 GL Nijmegen, The Netherlands
³ Institut für Theoretische Astrophysik, Zentrum für Astronomie der Universität Heidelberg, Albert-Ueberle-Str. 2, 69120 Heidelberg, Germany
e-mail: dullemond@uni-heidelberg.de
⁴ Max Planck Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany

Received: 2 February 2011
Accepted: 11 May 2011

Abstract

We study the effect of radiation pressure on the dust in the inner rim of transitional disks with large inner holes. In particular, we evaluate whether radiation pressure can be responsible for keeping the inner holes dust-free, while allowing gas accretion to proceed. This has been proposed in a paper by Chiang & Murray-Clay (2007, Nature Phys., 3, 604) who explain the formation of these holes as an inside-out evacuation due to X-ray-triggered accretion of the innermost layer of the disk rim outside of the hole. We show that radiation pressure is clearly incapable of stopping dust from flowing into the hole because of dust pile-up and optical depth effects, and also because of viscous mixing. Other mechanisms need to be found to explain the persistence of the opacity hole in the presence of accretion, and we speculate on possible solutions.