Free access article

A&A 480, 859-877 (2008)
DOI: 10.1051/0004-6361:20077759

Coagulation, fragmentation and radial motion of solid particles in protoplanetary disks

F. Brauer, C. P. Dullemond, and Th. Henning

Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
    e-mail: brauer@mpia.de

(Received 30 April 2007 / Accepted 11 November 2007)

Abstract
The growth of solid particles towards meter sizes in protoplanetary disks has to circumvent at least two hurdles, namely the rapid loss of material due to radial drift and particle fragmentation due to destructive collisions. In this paper, we present the results of numerical simulations with more and more realistic physics involved. Step by step, we include various effects, such as particle growth, radial/vertical particle motion and dust particle fragmentation in our simulations. We demonstrate that the initial dust-to-gas ratio is essential for the particles to overcome the radial drift barrier. If this value is increased by a factor of 2 compared with the canonical value for the interstellar medium, km-sized bodies can form in the inner disk (<2 AU) within 10⁴ yrs. However, we find that solid particles get destroyed through collisional fragmentation. Only with the unrealistically high-threshold velocities needed for fragmentation to occur (>30 m/s), particles are able to grow to larger sizes in disks with low  values. We also find that less than 5% of the small dust grains remain in the disk after 1 Myr due to radial drift, no matter whether fragmentation is included in the simulations or not. In this paper, we also present considerable improvements to existing algorithms for dust-particle coagulation, which speed up the coagulation scheme by a factor of ~10⁴.

Key words: accretion, accretion disks -- circumstellar matter -- stars: formation -- stars: pre-main-sequence -- infrared: stars -- planetary systems: protoplanetary disks

© ESO 2008

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

• If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
• You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
• You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.