Structure and Composition of Two Transitional Circumstellar Disks in Corona Australis - Astrophysics > Solar and Stellar AstrophysicsReport as inadecuate




Structure and Composition of Two Transitional Circumstellar Disks in Corona Australis - Astrophysics > Solar and Stellar Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: The late stages of evolution of the primordial circumstellar diskssurrounding young stars are poorly understood, yet vital to constrain theoriesof planet formation. We consider basic structural models for the disks aroundtwo ~10 Myr-old members of the nearby RCrA association, RX J1842.9-3532 and RXJ1852.3-3700. We present new arcsecond-resolution maps of their 230 GHzcontinuum emission from the Submillimeter Array and unresolved CO3-2 spectrafrom the Atacama Submillimeter Telescope Experiment. By combining these datawith broadband fluxes from the literature and infrared fluxes and spectra fromthe catalog of the Formation and Evolution of Planetary Systems FEPS Legacyprogram on the Spitzer Space Telescope, we assemble a multiwavelength data setprobing the gas and dust disks. Using the Monte Carlo radiative transfer codeRADMC to model simultaneously the SED and millimeter continuum visibilities, wederive basic dust disk properties and identify an inner cavity of radius 16 AUin the disk around RX J1852.3-3700. We also identify an optically thin 5 AUcavity in the disk around RX J1842.9-3532, with a small amount of opticallythick material close to the star. The molecular line observations suggest anintermediate disk inclination in RX J1842.9-3532, consistent with the continuumemission. In combination with the dust models, the molecular data allow us toderive a lower CO content than expected, suggesting that the process of gasclearing is likely underway in both systems, perhaps simultaneously with planetformation.



Author: A. M. Hughes CfA, S. M. Andrews CfA, D. J. Wilner CfA, M. R. Meyer ETH Zurich, J. M. Carpenter Caltech, C. Qi CfA, A. S. Hales NR

Source: https://arxiv.org/







Related documents