TeV observations of Centaurus A

aInstitute for Cosmic Ray Research, University of Tokyo, Tokyo 188-8502, Japan bDept. of Physics and Math. Physics, University of Adelaide 5005, Australia cInstitute of Space and Astronautical Science, Kanagawa 229-8510, Japan dDept. of Physics, Yamagata University, Yamagata 990-8560, Japan eDept. of Physics, Tokyo Institute of Technology, Tokyo 152-8551, Japan fFaculty of Management Information, Yamanashi Gakuin University, Yamanashi 400-8575, Japan gDept. of Physics, Tokai University, Kanagawa 259-1292, Japan hSolar-Terrestrial Environment Lab., Nagoya University, Aichi 464-8601, Japan iNational Astronomical Observatory of Japan, Tokyo 181-8588, Japan jFaculty of Science, Ibaraki University, Ibaraki 310-8512, Japan kInstitute of Physical and Chemical Research, Saitama 351-0198, Japan lFaculty of Engineering, Kanagawa University, Kanagawa 221-8686, Japan