Free access article

Issue A&A Volume 402, Number 2, May I 2003 Page(s) 443 - 455 Section Galactic structure and dynamics DOI 10.1051/0004-6361:20030247

A&A 402, 443-455 (2003)
DOI: 10.1051/0004-6361:20030247

Evidence of TeV gamma-ray emission from the nearby starburst galaxy NGC 253

C. Itoh¹, R. Enomoto², S. Yanagita¹, T. Yoshida¹, T. Tanimori³, K. Okumura², A. Asahara³, G. V. Bicknell⁴, R. W. Clay⁵, P. G. Edwards⁶, S. Gunji⁷, S. Hara^{3, 8}, T. Hara⁹, T. Hattori¹⁰, Shin. Hayashi¹¹, Sei. Hayashi¹¹, S. Kabuki², F. Kajino¹¹, H. Katagiri², A. Kawachi², T. Kifune¹², H. Kubo³, J. Kushida^{3, 8}, Y. Matsubara¹³, Y. Mizumoto¹⁴, M. Mori², H. Moro¹⁰, H. Muraishi¹⁵, Y. Muraki¹³, T. Naito⁹, T. Nakase¹⁰, D. Nishida³, K. Nishijima¹⁰, M. Ohishi², J. R. Patterson⁵, R. J. Protheroe⁵, K. Sakurazawa⁸, D. L. Swaby⁵, F. Tokanai⁷, K. Tsuchiya², H. Tsunoo², T. Uchida², A. Watanabe⁷, S. Watanabe³ and T. Yoshikoshi<sup>16

1</sup>  Faculty of Science, Ibaraki University, Mito, Ibaraki 310-8512, Japan
²  Institute for Cosmic Ray Research, Univ. of Tokyo, Kashiwa, Chiba 277-8582, Japan
³  Department of Physics, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
⁴  MSSSO, Australian National University, ACT 2611, Australia
⁵  Department of Physics and Math. Physics, University of Adelaide, SA 5005, Australia
⁶  Institute for Space and Aeronautical Science, Sagamihara, Kanagawa 229-8510, Japan
⁷  Department of Physics, Yamagata University, Yamagata, Yamagata 990-8560, Japan
⁸  Department of Physics, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan
⁹  Faculty of Management Information, Yamanashi Gakuin University, Kofu,Yamanashi 400-8575, Japan
¹⁰  Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan
¹¹  Department of Physics, Konan University, Hyogo 658-8501, Japan
¹²  Faculty of Engineering, Shinshu University, Nagano, Nagano 380-8553, Japan
¹³  STE Laboratory, Nagoya University, Nagoya, Aichi 464-8601, Japan
¹⁴  National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588, Japan
¹⁵  Department of Radiological Sciences, Ibaraki Prefectural University of Health Sciences, Ibaraki 300-0394, Japan
¹⁶  Department of Physics, Osaka City University, Osaka, Osaka 558-8585, Japan

(Received 5 November 2002 / Accepted 14 February 2003)

Abstract
TeV gamma-rays were recently detected from the nearby normal spiral galaxy NGC 253 (Itoh et al. 2002). Observations to detect the Cherenkov light images initiated by gamma-rays from the direction of NGC 253 were carried out in 2000 and 2001 over a total period of ~150 hours. The orientation of images in gamma-ray-like events is not consistent with emission from a point source, and the emission region corresponds to a size greater than 10 kpc in radius. Here, detailed descriptions of the analysis procedures and techniques are given.

Key words: gamma rays: observation -- galaxies: starburst -- galaxies: individual: NGC 253 -- galaxies: halos -- ISM: cosmic rays

Offprint request: R. Enomoto, enomoto@icrr.u-tokyo.ac.jp

SIMBAD Objects

© ESO 2003

What is OpenURL?