The early phase of star formation: Disk and Jet formation

  In star-forming regions, rotating disks and supersonic jets are seen  associated with central protostars.  However, it is still uncertain when and how the disks and jets can be formed.  In particular, their formation process is believed to be complicated by the presence of magnetic field.  To unveil the formation process of the disks and jets, we have observed some  young nearby protostellar systems, with Submillimeter Array (SMA) and Atacama Large Millimeter/submillimeter Array (ALMA).  We find that our results are consistent with current theoretical models.  In this talk, I will present some of our results for discussions.