ar X iv : a st ro - p h / 02 09 48 7 v 1 2 4 Se p 20 02 Observation of gamma - rays greater than 10 TeV from Markarian 421

We have observed Markarian 421 in January and March 2001 with the CANGAROO-II imaging Cherenkov telescope during an extraordinarily high state at TeV energies. From 14 hours observations at very large zenith angles, Institute for Cosmic Ray Research, University of Tokyo, Chiba 277-8582, Japan Department of Physics, Kyoto University, Kyoto 606-8502, Japan MSSSO, Australian National University, ACT 2611, Australia Institute of Space and Astronautical Science, Kanagawa 229-8510, Japan Department of Physics, Yamagata University, Yamagata 990-8560, Japan Department of Physics, Tokyo Institute of Technology, Tokyo 152-8551, Japan Faculty of Management Information, Yamanashi Gakuin University, Yamanashi 400-8575, Japan Department of Physics, Konan University, Hyogo 658-8501, Japan Faculty of Science, Ibaraki University, Ibaraki 310-8512, Japan Faculty of Engineering, Shinshu University, Nagano 380-8553, Japan STE Laboratory, Nagoya University, Aichi 464-8601, Japan National Astronomical Observatory of Japan, Tokyo 181-8588, Japan Ibaraki Prefectural University of Health Sciences, Ibaraki 300-0394, Japan Department of Physics, Tokai University, Kanagawa 259-1292, Japan Department of Physics and Math. Physics, University of Adelaide, SA 5005, Australia Department of Physics, Osaka City University, Osaka 558-858, Japan