A Northern Sky Survey for Steady Tera-Electron Volt Gamma-Ray Point Sources Using the Tibet Air Shower Array

• Published in: The Astrophysical journal 2005-11, Vol.633 (2), p.1005-1012
• Main Authors: Amenomori, M, Ayabe, S, Chen, D, Cui, S. W, Danzengluobu, Ding, L. K, Ding, X. H, Feng, C. F, Feng, Z. Y, Gao, X. Y, Geng, Q. X, Guo, H. W, He, H. H, He, M, Hibino, K, Hotta, N, Hu, Haibing, Hu, H. B, Huang, J, Huang, Q, Jia, H. Y, Kajino, F, Kasahara, K, Katayose, Y, Kato, C, Kawata, K, Labaciren, Le, G. M, Li, J. Y, Lu, H, Lu, S. L, Meng, X. R, Mizutani, K, Mu, J, Munakata, K, Nagai, A, Nanjo, H, Nishizawa, M, Ohnishi, M, Ohta, I, Onuma, H, Ouchi, T, Ozawa, S, Ren, J. R, Saito, T, Sakata, M, Sasaki, T, Shibata, M, Shiomi, A, Shirai, T, Sugimoto, H, Takashima, M, Takita, M, Tan, Y. H, Tateyama, N, Torii, S, Tsuchiya, H, Udo, S, Utsugi, T, Wang, H, Wang, X, Wang, Y. G, Wu, H. R, Xue, L, Yamamoto, Y, Yan, C. T, Yang, X. C, Yasue, S, Ye, Z. H, Yu, G. C, Yuan, A. F, Yuda, T, Zhang, H. M, Zhang, J. L, Zhang, N. J, Zhang, X. Y, Zhang, Yi, Zhang, Y, Zhaxisangzhu, Zhou, X. X
• Format: Article
• Language: English
• Subjects: Astronomy; Earth, ocean, space; Exact sciences and technology
• ISSN: 0004-637X; 1538-4357
• DOI: 10.1086/491612

Results of a steady TeV g-ray point-source search using data taken from the Tibet HD (1997 February -1999 September) and Tibet III (1999 November-2001 October) arrays are presented. From 0 to 60 in declination, significant excesses from the well-known steady source Crab Nebula and the high state of the flare-type source Markarian 421 are observed. Because the levels of significance from other positions are not sufficiently high, 90% confidence level upper limits on the flux are set assuming different power-law spectra. To allow cross-checking, two independently developed analyses are used in this work.