Investigating planet formation in circumstellar disks: CARMA observations of RY Tau and DG Tau - Astrophysics > Solar and Stellar AstrophysicsReportar como inadecuado




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Abstract: Abridged We present CARMA observations of the thermal dust emission fromthe circumstellar disks around the young stars RYTau and DGTau at wavelengthsof 1.3mm and 2.8mm. The angular resolution of the maps is as high as0.15arcsec, or 20AU at the distance of the Taurus cloud, which is a factor of 2higher than has been achieved to date at these wavelengths. The unprecedenteddetail of the resulting disk images enables us to address three importantquestions related to the formation of planets. 1 What is the radialdistribution of the circumstellar dust? 2 Does the dust emission show anyindication of gaps that might signify the presence of proto-planets? 3 Dothe dust properties depend on the orbital radius? We find that modeling thedisk surface density in terms of either a classical power law or the similaritysolution for viscous disk evolution, reproduces the observations well. The1.3mm image from RYTau shows two peaks separated by 0.2arcsec with a decline inthe dust emission toward the stellar position, which is significant at about2-4sigma. For both RYTau and DGTau, the dust emission at radii larger than 15AU displays no significant deviation from an unperturbed viscous disk model. Inparticular, no radial gaps in the dust distribution are detected. Underreasonable assumptions, we exclude the presence of planets more massive than 5Jupiter masses orbiting either star at distances between about 10 and 60 AU.The radial variation of the dust opacity slope, beta, was investigated bycomparing the 1.3mm and 2.8mm observations. We find mean values of beta of 0.5and 0.7 for DGTau and RYTau respectively. Variations in beta are smaller than0.7 between 20 and 70 AU. These results confirm that the circumstellar dustthroughout these disks differs significantly from dust in the interstellarmedium.



Autor: Andrea Isella, John M. Carpenter, Anneila I. Sargent

Fuente: https://arxiv.org/







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