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arXiv · 2108.01829

Catalog of Gamma-ray Glows during Four Winter Seasons in Japan

Yuuki Wada·Takahiro Matsumoto·Teruaki Enoto·Kazuhiro Nakazawa·Takayuki Yuasa·Yoshihiro Furuta·Daisuke Yonetoku·Tatsuya Sawano·Go Okada·Hidehito Nanto·Shohei Hisadomi·Yuna Tsuji·Gabriel Sousa Diniz·Kazuo Makishima·Harufumi Tsuchiya
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Abstract

In 2015 the Gamma-Ray Observation of Winter Thunderstorms (GROWTH) collaboration launched a mapping observation campaign for high-energy atmospheric phenomena related to thunderstorms and lightning discharges. This campaign has developed a detection network of gamma rays with up to 10 radiation monitors installed in Kanazawa and Komatsu cities, Ishikawa Prefecture, Japan, where low-charge-center winter thunderstorms frequently occur. During four winter seasons from October 2016 to April 2020, in total 70 gamma-ray glows, minute-lasting bursts of gamma rays originating from thunderclouds, were detected. Their average duration is 58.9 sec. Among the detected events, 77% were observed in nighttime. The gamma-ray glows can be classified into temporally-symmetric, temporally-asymmetric, and lightning-terminated types based on their count-rate histories. An averaged energy spectrum of the gamma-ray glows is well fitted with a power-law function with an exponential cutoff, whose photon index, cutoff energy, and flux are $0.613\pm0.009$, $4.68\pm0.04$ MeV, and $(1.013\pm0.003)\times10^{-5}$ erg cm$^{-2}$ s$^{-1}$ (0.2-20.0MeV), respectively. The present paper provides the first catalog of gamma-ray glows and their statistical analysis detected during winter thunderstorms in the Kanazawa and Komatsu areas.

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Yuuki Wada, Takahiro Matsumoto, Teruaki Enoto, Kazuhiro Nakazawa, Takayuki Yuasa, Yoshihiro Furuta, Daisuke Yonetoku, Tatsuya Sawano, Go Okada, Hidehito Nanto, Shohei Hisadomi, Yuna Tsuji, Gabriel Sousa Diniz, Kazuo Makishima, Harufumi Tsuchiya. 2021-08-04. Catalog of Gamma-ray Glows during Four Winter Seasons in Japan. https://arxiv.org/abs/2108.01829

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