Class I Sources in Taurus
Class I sources are generally thought to be young, deeply embedded protostars that have accumulated most of their final stellar mass but are still accreting at a significant rate. We studied a sample of low-mass Class I sources in Taurus and modeled properties of the circumstellar dust, such as geometry, dust grain properties, and mass accretion rates. This modeling utilized a new, multi-wavelength imaging+SED dataset consisting of 3mm photometry and high resolution 1mm images from OVRO, scattered light images at 0.9 microns from Keck, and spectral energy distributions from the literature and new data. We concluded that Class I sources appear to be surrounded by massive disks still embedded in massive envelopes. Furthermore, we argued that these massive disks are nearly gravitationally unstable, supporting the hypothesis that Class I objects may periodically undergo episodes of enhanced accretion through a disk instability (Eisner et al. 2005). We are currently using the new CARMA telescope to probe the inner regions of these disk/envelope systems to obtain better estimates of the disk masses, and thereby test this disk instability scenario.


Josh Eisner; July 7, 2008