The HH212 Protostar as Observed by ALMA: the Jet, the Cavity, and the Forming Disk

摘要

We report ALMA observations of HH212, a protostar driving a strikingly bipolar H2/SiO collimated jet. We show how ALMA-Band 7 data can trace in unprecedented detail, and within a single spectral set-up, all the crucial ingredients involved in the star-disk formation recipe, namely: (i) the dusty protostar; (ii) the axial jet launched from it; (iii) the biconical outflow and its cavities; (iv) the parent infalling envelope; (v) the forming disk. We reveal different kinematics among chemical tracers, and more asymmetric structures than predicted by simple models, with significant contribution from the rotating swept-up cavity. In particular, we focus on the C~(17)0 emission indicating a combination of infall and rotation, with a keplerian disk nested inside