Multiple components in the protostellar system HH 212: Infalling envelope, nested shell, MHD disk winds, and free wind gas

I will present the Atacama Large Millimeter/submillimeter Array Band 7 observations at ~24 au spatial resolution of the CO (J=3-2) and H13CO molecular lines emission of the protostellar system HH 212 and compare them with the emission of the SiO (J=8-7) and SO (J=8-7) molecular lines. From the large to small scale, previous observations have detected the infalling envelope, CO outflow shell, SO disk wind, SiO expanding shell and jet in the system. By comparing these components, we find that the CO molecular line traces four different regions of the system: (1) the external nested shell, (2) the wide-angle magnetohydrodynamic (MHD) disk winds, (3) free wind gas inside the expanding SiO shell, and (4) the protostellar jet. The origin of the CO external nested shell could be associated with the entrained material of the envelope either by the jet-driven bow shocks or by an outflowing gas launched from the central star or the accretion disk. As found in a previous SO study, the wide-angle MHD disk winds are launched directly from the accretion disk from a region of Rlaunch~4-8 au  and with a magnetic lever arm  3.5-4.5. The CO free wind gas inside the expanding SiO shell could be associated with material ejected directly from the accretion disk.