A Rotating Disk in the HH 111 Protostellar System

Abstract: The HH 111 protostellar system is a young Class I system with two sources, VLA 1 and VLA 2, at a distance of 400 pc. Previously, a flattened envelope has been seen in C18O to be in transition to a rotationally supported disk near the VLA 1 source. The follow-up study here is to confirm the rotationally supported disk at 2-3 times higher angular resolutions, at ~ 0.3" (or 120 AU) in 1.33 mm continuum, and ~ 0.6" (or 240 AU) in 13CO (J=2-1) and 12CO (J=2-1) emission obtained with the Submillimeter Array. The 1.33 mm continuum emission shows a resolved dusty disk associated with the VLA 1 source perpendicular to the jet axis, with a Gaussian deconvolved size of ~ 240 AU. The 13CO and 12CO emissions toward the dusty disk show a Keplerian rotation, indicating that the dusty disk is rotationally supported. The density and temperature distributions in the disk derived from a simple disk model are found to be similar to those found in bright T-Tauri disks, suggesting that the disk can evolve into a T-Tauri disk in the late stage of star formation. In addition, a hint of a low-velocity molecular outflow is also seen in 13CO and 12CO coming out from the disk.