Probing the Embedded YSOs of the R CrA Region Through VLT-ISAAC Spectroscopy

Abstract

The low and medium resolution spectra, obtained with ISAAC at VLT, of five embedded Young Stellar Objects (YSOs) in the R CrA star forming core have been analyzed in order to constrain the nature of the central objects and their circumstellar environments. From the medium resolution spectra we were able to detect photospheric absorption features in all the observed targets, including the Class I sources HH100 IR and R CrA IRS2, whose low resolution spectra only present several lines in emission. We derived the stellar parameters and the amount of IR excess of all the five observed sources, which in turn have been used to infer their accretion luminosity. The knowledge of these parameters allowed to settle the relative evolutionary state among the observed sources. This study shows how high resolution near IR spectroscopy, coupled with a high sensitivity, is a very powerful tool to reveal the nature of embedded young stellar objects since their accretion phase.