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          Institute: MPI für Radioastronomie     Collection: Publikationen des MPI für Radioastronomie     Display Documents



ID: 11052.0, MPI für Radioastronomie / Publikationen des MPI für Radioastronomie
Evidence for a developing gap in a 10 Myr old protoplanetary disk
Authors:Calvet, N.; D'Alessio, P.; Hartmann, L.; Wilner, D.; Walsh, A.; Sitko, M.
Language:English
Date of Publication (YYYY-MM-DD):2002-04-01
Title of Journal:Astrophysical Journal
Journal Abbrev.:Astrophys. J.
Volume:568
Issue / Number:2
Start Page:1008
End Page:1016
Review Status:Peer-review
Audience:Experts Only
Abstract / Description:We have developed a physically self-consistent model of the disk around the nearby 10 Myr old star TW Hya that matches the observed spectral energy distribution and 7 mm images of the disk. The model requires both significant dust-size evolution and a partially evacuated inner disk region, as predicted by theories of planet formation. The outer disk, which extends to at least 140 AU in radius, is very optically thick at infrared wavelengths and quite massive (similar to0.06 M-.) for the relatively advanced age of this T Tauri star. This implies long viscous and dust evolution timescales, although dust must have grown to sizes of the order of similar to1 cm to explain the submillimeter and millimeter spectral slopes. In contrast, the negligible near-infrared excess emission of this system requires that the disk be optically thin inside. 4 AU. This inner region cannot be completely evacuated; we need similar to0.5 lunar mass of similar to1 mum particles remaining to produce the observed 10 mum silicate emission. Our model requires a distinct transition in disk properties at 4 AU separating the inner and outer disks. The inner edge of the optically thick outer disk must be heated almost frontally by the star to account for the excess flux at mid-infrared wavelengths. We speculate that this truncation of the outer disk may be the signpost of a developing gap due to the effects of a growing protoplanet; the gap is still presumably evolving because material still resides in it, as indicated by the silicate emission, the molecular hydrogen emission, and the continued accretion onto the central star ( albeit at a much lower rate than typical of younger T Tauri stars). Thus, TW Hya may become the Rosetta stone for our understanding of the evolution and dissipation of protoplanetary disks.
Free Keywords:accretion; accretion disks; circumstellar matter; stars : formation; stars : pre main-sequence
External Publication Status:published
Document Type:Article
Communicated by:N. N.
Affiliations:MPI für Radioastronomie
External Affiliations:Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA; 02138 USA; Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA; Natl Autonomous Univ Mexico, Inst Astron, Mexico City 04510, DF, Mexico; Amer Museum Nat Hist, New York, NY 10024 USA; Max Planck Inst Radioastron, D-53121 Bonn, Germany; Univ Cincinnati, Dept Phys, Cincinnati, OH 45221 USA
Identifiers:ISI:000174625700044
ISSN:0004-637X
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