PIÉTU, Vincent; DUTREY, Anne; GUILLOTEAU, S.

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PIÉTU, Vincent
Institut de RadioAstronomie Millimétrique [IRAM]

DUTREY, Anne
Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux [L3AB]
Observatoire aquitain des sciences de l'univers [OASU]
Laboratoire d'Astrophysique de Bordeaux [Pessac] [LAB]
Université Sciences et Technologies - Bordeaux 1 [UB]

GUILLOTEAU, S.
Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux [L3AB]
Observatoire aquitain des sciences de l'univers [OASU]
Laboratoire d'Astrophysique de Bordeaux [Pessac] [LAB]
Université Sciences et Technologies - Bordeaux 1 [UB]

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Article de revue

Ce document a été publié dans

Astronomy and Astrophysics - A&A. 2007, vol. 467, n° 1, p. 163-178

EDP Sciences

Résumé en anglais

We report sub-arcsec CO observations of the disks around MWC 480, LkCa 15 and DM Tau, and simultaneous measurements of HCO+ J=1-0. We derive the disk properties by fitting a standard disk model, with all parameters power laws of the distance to the star. Biases are explained and discussed. We find evidence for vertical temperature gradient in the disks of MWC 480 and DM Tau, as in AB Aur, but not in LkCa 15. The disks temperature increase with stellar effective temperature. Most of the CO gas is at temperatures smaller than 17 K, the condensation temperature on grains. The scale height of the CO distribution appears larger (by 50\%) than the hydrostatic scale height. The more UV luminous stars have more CO, but there is no simple dependency of CO abundance and isotopologue ratio with stellar type. The 13CO/HCO+ ratio is around 600. The temperature behaviour is consistent with expectations, but published chemical models have difficulty reproducing the observed CO quantities. Vertical mixing and photo-dissociation at the disk outer edge seem important chemical agents. The CO data suggest a more complex surface density distribution than assumed in models.< Réduire

Mots clés en anglais

Stars: circumstellar matter

planetary systems: protoplanetary disks

individual: LkCa 15

MWC 480

DM Tau

Radio-lines: stars

Origine

Importé de hal

Unités de recherche

Laboratoire d'Astrophysique de Bordeaux (LAB) - UMR 5804