1. Mizusawa VLBI Observatory, National Astronomical Observatory of Japan , 2-12 Hoshiga-oka, Mizusawa, Oshu-shi, Iwate 023-0861, Japan
2. Amanogawa Galaxy Astronomy Research Center, Graduate School of Science and Engineering, Kagoshima University , 1-21-35 Korimoto, Kagoshima, Kagoshima 890-0065, Japan
3. Center for General Education, Institute for Comprehensive Education, Kagoshima University , 1-21-30 Korimoto, Kagoshima, Kagoshima 890-0065, Japan
4. Department of Astronomy, School of Science, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
5. The Graduate University for Advanced Studies , SOKENDAI, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
6. Toyo University , 5-28-20 Hakusan, Bunkyo-ku, Tokyo 112-8606, Japan
7. Mizusawa VLBI Observatory, National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan