Detection of Multi‐TeV Gamma Rays from Markarian 501 during an Unforeseen Flaring State in 1997 with the Tibet Air Shower Array
Year: 2000
Type: article
Abstract: In 1997, the BL Lac object Mrk 501 entered a very active phase and was the brightest source in the sky at TeV energies, showing strong and frequent flaring. Using the data obtained with a high-density air shower array that has been operating successfully at Yangbajing in Tibet since 1996, we searched for γ-ray signals from this source during the period in 1997 from February through August. Our observation detected multi-TeV γ-ray signals at the 3.7 σ level during this period. The most rapid increase in the excess counts was observed between April 7 and June 16, and the statistical significance of the excess counts in this period was 4.7 σ. Among several observations of flaring TeV γ-rays from Mrk 501 in 1997, this is the only observation using a conventional air shower array. We present the energy spectrum of γ-rays, which will be worth comparing with those obtained by imaging atmospheric Cerenkov telescopes.
Source: The Astrophysical Journal
DOI: 10.1086/308558
Authors: M. Amenomori, S. Ayabe, P. Y. Cao, Danzengluobu, L. K. Ding, Z. Y. Feng, Y. Fu, H. W. Guo, M. He, K. Hibino, N. Hotta, Q. Huang, A. X. Huo, K. Izu, H. Y. Jia, F. Kajino, K. Kasahara, Y. Katayose, Labaciren, J. Y. Li, H. Lu, S. L. Lu, G. X. Luo, X. R. Meng, K. Mizutani, J. Mu, H. Nanjo, M. Nishizawa, M. Ohnishi, I. Ohta, T. Ouchi, J. R. Ren, T. Saito, M. Sakata, T. Sasaki, Z. Z. Shi, M. Shibata, A. Shiomi, T. Shirai, H. Sugimoto, K. Taira, Y. H. Tan, N. Tateyama, S. Torii, T. Utsugi, C. R. Wang, H. Wang, X. W. Xu, Y. Yamamoto, G. C. Yu, A. F. Yuan, T. Yuda, C. S. Zhang, H. M. Zhang, J. L. Zhang, N. J. Zhang, X. Y. Zhang, Zhaxisangzhu, Zhaxiciren, W. D. Zhou
Institutions: Hirosaki University, Saitama University, Shandong University, Tibet University, Institute of High Energy Physics, Southwest Jiaotong University, Kanagawa University, Utsunomiya University, Institute for Cosmic Ray Research, The University of Tokyo, Konan University, Shibaura Institute of Technology, Yunnan University, Yokohama National University, Shonan Institute of Technology
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2137166120