EDP Sciences
Free Access
Issue
A&A
Volume 400, Number 3, March IV 2003
Page(s) L21 - L24
Section Letters
DOI https://doi.org/10.1051/0004-6361:20030141
Published online 07 March 2003


A&A 400, L21-L24 (2003)
DOI: 10.1051/0004-6361:20030141

Letter

Grain growth in the inner regions of Herbig Ae/Be star disks

R. van Boekel1, 2, L. B. F. M. Waters2, 3, C. Dominik2, J. Bouwman4, A. de Koter2, C. P. Dullemond5 and F. Paresce1

1  European Southern Observatory, Karl-Schwarzschildstrasse 2, 85748 Garching bei München, Germany
2  Astronomical Institute "Anton Pannekoek", University of Amsterdam, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands
3  Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200B, 3001 Heverlee, Belgium
4  CEA, DSM, DAPNIA, Service d'Astrophysique, CEN Saclay, 91191 Gif-sur-Yvette Cedex, France
5  Max-Planck-Institut für Astrophysik, Karl-Schwarzschildstrasse 1, Postfach 1317, 85748 Garching bei München, Germany

(Received 19 September 2002 / Accepted 2 February 2003)

Abstract
We present new mid-infrared spectroscopy of the emission from warm circumstellar dust grains in Herbig Ae/Be stars. Our survey significantly extends the sample that was studied by Bouwman et al. (2001). We find a correlation between the strength of the silicate feature and its shape. We interpret this as evidence for the removal of small (0.1  $\mu$m) grains from the disk surface while large (1-2  $\mu$m) grains persist. If the evolution of the grain size distribution is dominated by gravitational settling, large grains are expected to disappear first, on a timescale which is much shorter than the typical age of our programme stars. Our observations thus suggest a continuous replenishment of micron sized grains at the disk surface. If the grain replenishment is due to the dredge-up of dust from the disk interior, the mineralogy we observe is representative of the bulk composition of dust in these stars.


Key words: stars: circumstellar matter -- stars: pre-main-sequence -- infrared: ISM: lines and bands

Offprint request: R. van Boekel, rvanboek@eso.org

SIMBAD Objects



© ESO 2003

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.