INFALL AND OUTFLOW AROUND THE HH 212 PROTOSTELLAR SYSTEM

摘要

HH 212 is a highly collimated jet discovered in H_2 powered by a young Class 0 source, IRAS 05413-0104, in the L1630 cloud of Orion. We have mapped around it in 1.33 mm continuum, ~(12)CO (J = 2-1), ~(13)CO (J = 2-1), C~(18)O (J = 2-1), and SO (N_J = 5_6-4_5) emission at ～2.5″ resolution with the Submillimeter Array. A dust core is seen in the continuum around the source. A flattened envelope is seen in C~(18)O around the source in the equator perpendicular to the jet axis, with its inner part seen in ~(13)CO. The structure and kinematics of the envelope can be roughly reproduced by a simple edge-on disk model with both infall and rotation. In this model, the density of the disk is assumed to have a power-law index of p = - 1.5 or-2, as found in other low-mass envelopes. The envelope seems dynamically infalling toward the source with slow rotation because the kinematics is found to be roughly consistent with a free fall toward the source plus a rotation of a constant specific angular momentum. A ~(12)CO outflow is seen surrounding the H_2 jet, with a narrow waist around the source. Jetlike structures are also seen in ~(12)CO near the source aligned with the H_2 jet at high velocities. The morphological relationship between the H_2 jet and the ~(12)CO outflow, and the kinematics of the ~(12)CO outflow along the jet axis, are both consistent with those seen in a jet-driven bow shock model. SO emission is seen around the source and the H_2 knotty shocks in the south, tracing shocked emission around them.