T. Nakamori, H. Kubo, T. Yoshida, T. Tanimori, R. Enomoto, G. V. Bicknell, R. W. Clay, P. G. Edwards, S. Gunji, S. Hara, T. Hara, T. Hattori, S. Hayashi, Y. Higashi, Y. Hirai, K. Inoue, S. Kabuki, F. Kajino, H. Katagiri, A. Kawachi, T. Kifune, R. Kiuchi, J. Kushida, Y. Matsubara, T. Mizukami, Y. Mizumoto, R. Mizuniwa, M. Mori, H. Muraishi, Y. Muraki, T. Naito, S. Nakano, D. Nishida, K. Nishijima, M. Ohishi, Y. Sakamoto, A. Seki, V. Stamatescu, T. Suzuki, D. L. Swaby, G. Thornton, F. Tokanai, K. Tsuchiya, S. Watanabe, Y. Yamada, E. Yamazaki, S. Yanagita, T. Yoshikoshi, and Y. Yukawa
We have observed the supernova remnant MSH 15-52 (G320.4-1.2), which contains the gamma-ray pulsar PSR B1509-58, using the CANGAROO-III imaging atmospheric Cerenkov telescope array from 2006 April to June. We detected gamma rays above 810 GeV at the 7σ level during a total effective exposure of 48.4 hr. We obtained a differential gamma-ray flux at 2.35 TeV of (7.9+-1.5stat+-1.7sys)× 10-13cm-2s-1TeV-1, with a photon index of 2.21+-0.39stat+-0.40sys, which is compatible with that of the H.E.S.S. observation in 2004. The morphology shows extended emission compared to our point spread function. We consider the plausible origin of the high-energy emission based on a multiwavelength spectral analysis and energetics arguments.