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| EPoS Contribution |
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Molecular outflow/jets and circumstellar component around a young protostar L1448C
Masaaki Hiramatsu Academia Sinica Institute of Astronomy and Astrophysics, Hsinchu, Taiwan | |
| We present the results of the SMA archival data for a very young protostar L1448C in emission of CO (2-1), SO (5_6-4_5), and C18O (2-1). A bipolar outflow emanated from L1448C is clearly detected in CO (2-1). In the low velocity (< 20 km/s) range, the CO emission shows two V-shaped structures which correspond to the bipolar cavity walls. The highly collimated and high velocity (upto 70 km/s) CO jet is also detected along the axes of the V-shaped cavity. This collimated jet is also seen in the SO (5_6-4_5) line in the velocity range of 5 - 60 km/s with respect to the systemic velocity. This SO jet has knotty structure and is more luminous in the vicinity of the driving source. The 230 GHz continuum emission shows compact distribution around L1448C with a deconvolved size of 460 AU x 190 AU. The mass is estimated to be 0.06 Msun on the assumption of the dust temperature of 40 K. The compact circumstellar component is also detected in C18O (2-1), and this C18O component has a velocity gradient of 0.48 km/s in 730 AU (the inclination is assumed to be 69 deg). The enclosed mass estimated from the velocity gradient is 0.19 Msun and comparable to the sum of the mass of the central star (~0.09Msun) and the compact circumstellar component detected with the 230 GHz continuum emission, which suggests that this structure would be rotationally supported. The local specific angular momentum is estimated to be 1.7x10^{-3} km/s pc, which is comparable to those of the rotating envelopes/disks around other protostars. This local specific angular momentum is one order of magnitude smaller than that at 3000 AU scale, suggesting the angular momentum is not conserved in the star formation process. | |
| Collaborators: N. Hirano, ASIAA, Taiwan H.-R. Chen, NTHU, Taiwan |
Suggested Session: Cores and Collapse, Early Phases of Disks |