Radial mixing in protoplanetary accretion disks

Free access article

Issue		A&A Volume 410, Number 3, November II 2003


Page(s)		917 - 935
Section		Formation, structure and evolution of stars
DOI		http://dx.doi.org/10.1051/0004-6361:20031316

A&A 410, 917-935 (2003)
DOI: 10.1051/0004-6361:20031316

V. Models with different element mixtures

M. Wehrstedt and H.-P. Gail

Institut für Theoretische Astrophysik, Universität Heidelberg, Tiergartenstraße 15, 69121 Heidelberg, Germany
(Received 17 June 2003 / Accepted 14 August 2003)

Abstract
Protoplanetary disks as birth places of planets as well as of their host stars bear different element mixtures owing to the different chemical compositions of the environments where they are born. The chemical composition affects the structure and evolution of the disks, particularly the composition and abundance of the dust. In this work we perform one-zone model calculations of vertically selfgravitating protoplanetary accretion disks with the $\beta$ -prescription for the viscosity with different element mixtures. The models consider the chemical equilibrium condensation of the most important dust species in the disk as well as annealing of interstellar silicate dust and combustion of carbon dust. Also a new inner boundary condition is introduced which avoids the unphysical decline of the surface density $\Sigma$ of the frequently adopted no-torque ( $\Sigma=0$ ) condition. The main result of the model calculations is that with decreasing metallicity the disks become less opaque and hence colder as a consequence of the reduced dust-to-gas ratio. Further we give a rough estimate for the critical value of the metallicity below which the formation of terrestrial planets is inhibited.

Key words: accretion, accretion disks -- stars: abundances -- solar system: formation -- dust, extinction

Offprint request: M. Wehrstedt, mwehrste@ita.uni-heidelberg.de

SIMBAD Objects

What is OpenURL?

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.