Volume 460, Number 3, December IV 2006
|Page(s)||L43 - L47|
|Published online||24 October 2006|
Letter to the Editor
Resolving the inner dust disks surrounding LkCa 15 and MWC 480 at mm wavelengths
IRAM, 300 rue de la piscine, 38406 Saint Martin d'Hères, France e-mail: firstname.lastname@example.org
2 L3AB, CNRS UMR5804, OASU, 2 rue de l'Observatoire, BP 89, 33270 Floirac, France
Accepted: 30 October 2006
Aims.We constrain the dust distribution and its properties (temperature, emissivity) in inner proto-planetary disks
Methods.We performed sub-arcsecond high-sensitivity interferometric observations of the thermal dust emission at 1.4 mm and 2.8 mm in the disks surrounding LkCa 15 and MWC 480, with the new 750 m baselines of the IRAM PdBI array. This provides a linear resolution of ~60 AU at the distance of Taurus.
Results.We report the existence of a cavity of ~50 AU radius in the inner disk of LkCa 15. Whereas LkCa 15 emission is optically thin, the optically thick core of MWC 480 is resolved at 1.4 mm with a radius of ~35 AU, constraining the dust temperature. In MWC 480, the dust emission is coming from a colder layer than the CO emission, most likely the disk mid-plane.
Conclusions.These observations provide direct evidence of an inner cavity around LkCa 15. Such a cavity most probably results from the tidal disturbance created by a low-mass companion or large planet at ~30 AU from the star. These results suggest that planetary system formation is already at work in LkCa 15. They also indicate that the classical steady-state viscous disk model is too simplistic a description of the inner 50 AU of “proto-planetary” disks and that the disk evolution is coupled to the planet formation process. The MWC 480 results indicate that a proper estimate of the dust temperature and size of the optically thick core are essential for determining the dust emissivity index β.
Key words: stars: circumstellar matter / planetary systems: protoplanetary disks / stars: individual: LkCa 15 / stars: individual: MWC 480 / radio-continuum: stars
© ESO, 2006
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.