CANGAROO-III Search for Gamma Rays from Centaurus A and the ω Centauri Region

S. Kabuki, R. Enomoto, G. V. Bicknell, R. W. Clay, P. G. Edwards, S. Gunji, S. Hara, T. Hattori, S. Hayashi, Y. Higashi, R. Inoue, C. Itoh7, F. Kajino, H. Katagiri, A. Kawachi, S. Kawasaki, T. Kifune, R. Kiuchi, K. Konno, H. Kubo, J. Kushida, Y. Matsubara, T. Mizukami, R. Mizuniwa, M. Mori, H. Muraishi, T. Naito, T. Nakamori, D. Nishida, K. Nishijima, M. Ohishi, Y. Sakamoto, V. Stamatescu, S. Suzuki, T. Suzuki, D. L. Swaby, T. Tanimori, G. Thornton, F. Tokanai, K. Tsuchiya, S. Watanabe, Y. Yamada, E. Yamazaki, S. Yanagita, T. Yoshida, T. Yoshikoshi, M. Yuasa, and Y. Yukawa

(Astrophys. J. in press)
We have observed the giant radio galaxy Centaurus A and the globular cluster &omega: Centauri in the TeV energy region using the CANGAROO-III stereoscopic system. The system has been in operation since 2004 with an array of four Imaging Atmospheric Cherenkov Telescopes (IACT) with ~100-m spacings. The observations were carried out in March and April 2004. In total, approximately 10 hours data were obtained for each target. No statistically significant gammaray signal has been found above 420 GeV over a wide angular region (a one-degree radius from the pointing center) and we derive flux upper limits using all of the field of view. Implications for the total energy of cosmic rays and the density of the cold dark matter are considered.