CANGAROO-III Observation of TeV Gamma Rays from the Vicinity of PSR B1706-44

R. Enomoto, J. Kushida, T. Nakamori, T. Kifune, 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, H. Ishioka, S. Kabuki, F. Kajino, H. Katagiri, A. Kawachi, R. Kiuchi, H. Kubo, T. Kunisawa, T. Matoba, Y. Matsubara, I. Matsuzawa, T. Mizukami, Y. Mizumura, Y. Mizumoto, M. Mori, H. Muraishi, T. Naito, S. Nakano, K. Nishijima, M. Ohishi, Y. Otake, S. Ryoki, K. Saito, Y. Sakamoto, A. Seki, V. Stamatescu, T. Suzuki, D. L. Swaby, T. Tanimori, G. Thornton, F. Tokanai, K. Tsuchiya, S. Watanabe, E. Yamazaki, S. Yanagita, T. Yoshida, T. Yoshikoshi, Y. Yukawa

(Astrophys. J. in press)
Observation by the CANGAROO-III stereoscopic system of the Imaging Cherenkov Telescope has detected extended emission of TeV gamma rays in the vicinity of the pulsar PSR B1706-44. The strength of the signal observed as gamma-ray-like events varies when we apply different ways of emulating background events. The reason for such uncertainties is argued in relevance to gamma rays embedded in the "OFF-source data," that is, unknown sources and diffuse emission in the Galactic plane, namely, the existence of a complex structure of TeV gamma-ray emission around PSR B1706-44.