Volume 525, January 2011
|Number of page(s)||8|
|Section||Interstellar and circumstellar matter|
|Published online||26 November 2010|
New constraints on dust grain size and distribution in CQ Tauri
ETH Zurich, Wolfgang-Pauli-Strasse 27, 8093
2 ESO, Karl Schwarzschild str. 2, 85748 Garching bei Muenchen, Germany
3 INAF – Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy
4 Division of Physics, Mathematics and Astronomy, California Institute of Technology, MC 249-17, Pasadena, CA 91125, USA
5 Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, 38406 Saint Martín d’Hères, France
6 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 42, Cambridge, MA 02138, USA
Received: 13 June 2010
Accepted: 3 September 2010
Context. Grain growth in circumstellar disks is expected to be the first step towards the formation of planetary systems. There is now evidence for grain growth in several disks around young stars.
Aims. Radially resolved images of grain growth in circumstellar disks are believed to be a powerful tool to constrain the dust evolution models and the initial stage for the formation of planets. In this paper we attempt to provide these constraints for the disk surrounding the young star CQ Tau. This system was already suggested from previous studies to host a population of grains grown to large sizes.
Methods. We present new high angular resolution (0.′′3−0.′′9) observations at wavelengths from 850 μm to 3.6 cm obtained at the SMA, IRAM-PdBI and NRAO-VLA interferometers. We perform a combined analysis of the spectral energy distribution and of the high-resolution images at different wavelengths using a model to describe the dust thermal emission from the circumstellar disk. We include a prescription for the gas emission from the inner regions of the system.
Results. We detect the presence of evolved dust by constraining the disk averaged dust opacity coefficient β (computed between 1.3 and 7 mm) to be 0.6 ± 0.1. This confirms the earlier suggestions that the disk contains dust grains grown to significant sizes and puts this on firmer grounds by tightly constraining the gas contamination to the observed fluxes at mm-cm wavelengths. We report some evidence of radial variations in dust properties, but current resolution and sensitivity are still too low for definitive results.
Key words: protoplanetary disks / dust, extinction / circumstellar matter / stars: individual: CQ Tauri
© ESO, 2010
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.