THE VLBI MONITORING PROJECT FOR 6.7 GHz METHANOL MASERS USING THE JVN/EAVN

We have initiated a Very Long Baseline Interferometer (VLBI) monitoring project of 36 methanol maser sources at 6.7 GHz using the Japanese VLBI Network (JVN) and East-Asian VLBI Network (EAVN), starting in August 2010. The purpose of this project is to systematically reveal 3-dimensional (3-D) kinematics of rotating disks around forming high-mass protostars. As an initial result, we present proper motion detections for two methanol maser sources showing an elliptical spatial morphology, G 002.53+00.19 and G 006.79−00.25, which could be the best candidates associated with the disk. The detected proper motions indicate a simple rotation in G 002.53+00.19 and rotation with expansion in G 006.79−00.25, respectively, on the basis of disk model fits with rotating and expanding components. The expanding motions might be caused by the magnetic-centrifugal wind on the disk.