EDP Sciences
Free access
Issue
A&A
Volume 385, Number 2, April II 2002
Page(s) 632 - 646
Section Formation and evolution of planetary systems
DOI http://dx.doi.org/10.1051/0004-6361:20020050


A&A 385, 632-646 (2002)
DOI: 10.1051/0004-6361:20020050

Molecular distributions in the inner regions of protostellar disks

A. J. Markwick1, M. Ilgner2, T. J. Millar1 and Th. Henning2

1  Department of Physics, UMIST, Sackville Street, Manchester M60 1QD, UK
    e-mail: Tom.Millar@umist.ac.uk
2  Astrophysical Institute and University Observatory (AIU), Friedrich Schiller University, Schillergaesschen 2-3, 07745 Jena, Germany
    e-mail: ilgner, henning@astro.uni-jena.de

(Received 5 September 2001 / Accepted 10 January 2002 )

Abstract
The distributions of molecules in the inner regions of a protostellar disk are presented. These were calculated using an uncoupled chemical/dynamical model, with a numerical integration of the vertical disk structure. A comparison between models with and without the effects of X-ray ionisation is made, and molecules are identified which are good tracers of the ionisation level in this part of the disk, notably CN and C 2H. In the region considered in this paper ( $r\leq 10$ AU), the chemistry is dominated by the thermal desorption of species from grains. This shows that a critically important detail in this region of the disk, as far as molecular distributions are concerned, is the temperature profile. We find that not all of the gaseous material is frozen onto grain surfaces at 10 AU, and we identify species, including some organic molecules, which should exist in observable quantities in the inner regions of protostellar disks.


Key words: solar system: formation -- stars: circumstellar matter -- stars: pre-main sequence -- ISM: molecules -- ISM: abundances -- stars: planetary systems: protoplanetary disks

Offprint request: A. J. Markwick, ajm@ajmarkwick.com

SIMBAD Objects in preparation



© ESO 2002