SMA observations of young disks: separating envelope, disk, and stellar masses in class I YSOs

Context. Young stars are born with envelopes, which in the early stages obscure the central (proto)star and circumstellar disk. In the Class I stage, the disks are still young, but the envelopes are largely dispersed. This makes the Class I sources ideal targets for studies of the early stages of disks. Aims. We aim to determine the masses of the envelopes, disks, and central stars of young stellar objects (YSOs) in the Class I stage. Methods. We observed the embedded Class I objects IRS 63 and Elias 29 in the ρ Ophiuchi star-forming region with the Submillimeter Array (SMA) at 1.1 mm. Results. IRS 63 and Elias 29 are both clearly detected in the continuum, with peak fluxes of 459 and 47 mJy/beam, respectively. The continuum emission toward Elias 29 is clearly resolved, whereas IRS 63 is consistent with a point source down to a scale of 3 ��