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1. Detection of Very High-energy Gamma-Ray Emission from the Radio Galaxy M87 with LHAASO

Author

Zhen Cao, F. Aharonian, Axikegu, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, W. Bian, A. V. Bukevich, Q. Cao, W. Y. Cao, Zhe Cao, J. Chang, J. F. Chang, A. M. Chen, E. S. Chen, H. X. Chen, Liang Chen, Lin Chen, Long Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, M. C. Chu, M. Y. Cui, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, Danzengluobu, X. Q. Dong, K. K. Duan, J. H. Fan, Y. Z. Fan, J. Fang, J. H. Fang, K. Fang, C. F. Feng, H. Feng, L. Feng, S. H. Feng, X. T. Feng, Y. Feng, Y. L. Feng, S. Gabici, B. Gao, C. D. Gao, Q. Gao, W. Gao, W. K. Gao, M. M. Ge, T. T. Ge, L. S. Geng, G. Giacinti, G. H. Gong, Q. B. Gou, M. H. Gu, F. L. Guo, J. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, O. A. Hannuksela, M. Hasan, H. H. He, H. N. He, J. Y. He, Y. He, Y. K. Hor, B. W. Hou, C. Hou, X. Hou, H. B. Hu, Q. Hu, S. C. Hu, C. Huang, D. H. Huang, T. Q. Huang, W. J. Huang, X. T. Huang, X. Y. Huang, Y. Huang, Y. Y. Huang, X. L. Ji, H. Y. Jia, K. Jia, H. B. Jiang, K. Jiang, X. W. Jiang, Z. J. Jiang, M. Jin, M. M. Kang, I. Karpikov, D. Khangulyan, D. Kuleshov, K. Kurinov, B. B. Li, C. M. Li, Cheng Li, Cong Li, D. Li, F. Li, H. B. Li, H. C. Li, Jian Li, Jie Li, K. Li, S. D. Li, W. L. Li, X. R. Li, Xin Li, Y. Z. Li, Zhe Li, Zhuo Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, D. B. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. Liu, Y. N. Liu, Q. Luo, Y. Luo, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, Z. Min, W. Mitthumsiri, H. J. Mu, Y. C. Nan, A. Neronov, K. C. Y. Ng, L. J. Ou, P. Pattarakijwanich, Z. Y. Pei, J. C. Qi, M. Y. Qi, B. Q. Qiao, J. J. Qin, A. Raza, D. Ruffolo, A. Sáiz, M. Saeed, D. Semikoz, L. Shao, O. Shchegolev, X. D. Sheng, F. W. Shu, H. C. Song, Yu. V. Stenkin, V. Stepanov, Y. Su, D. X. Sun, Q. N. Sun, X. N. Sun, Z. B. Sun, J. Takata, P. H. T. Tam, Q. W. Tang, R. Tang, Z. B. Tang, W. W. Tian, L. H. Wan, C. Wang, C. B. Wang, G. W. Wang, H. G. Wang, H. H. Wang, J. C. Wang, Kai Wang, L. P. Wang, L. Y. Wang, P. H. Wang, R. Wang, W. Wang, X. G. Wang, X. Y. Wang, Y. Wang, Y. D. Wang, Y. J. Wang, Z. H. Wang, Z. X. Wang, Zhen Wang, Zheng Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, Q. W. Wu, S. Wu, X. F. Wu, Y. S. Wu, S. Q. Xi, J. Xia, G. M. Xiang, D. X. Xiao, G. Xiao, Y. L. Xin, Y. Xing, D. R. Xiong, Z. Xiong, D. L. Xu, R. F. Xu, R. X. Xu, W. L. Xu, L. Xue, D. H. Yan, J. Z. Yan, T. Yan, C. W. Yang, C. Y. Yang, F. Yang, F. F. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, W. X. Yang, Y. H. Yao, Z. G. Yao, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. Yue, H. D. Zeng, T. X. Zeng, W. Zeng, M. Zha, B. B. Zhang, F. Zhang, H. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, Li Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. B. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. F. Zhang, Yi Zhang, Yong Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, X. H. Zhao, F. Zheng, W. J. Zhong, B. Zhou, H. Zhou, J. N. Zhou, M. Zhou, P. Zhou, R. Zhou, X. X. Zhou, B. Y. Zhu, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, Y. C. Zou, and X. Zuo

Subjects
Active galactic nuclei, High energy astrophysics, Astrophysics, QB460-466
Abstract

The nearby radio galaxy M87 is a very high-energy (VHE) gamma-ray emitter established by observations with ground-based gamma-ray detectors. Here we report the long-term monitoring of M87 from 2021 to 2024 with the Large High Altitude Air Shower Observatory (LHAASO). M87 has been detected by LHAASO with a statistical significance ∼ 9 σ . The observed energy spectrum extends to 20 TeV, with a possible hardening at ∼20 TeV and then a clear softening at higher energies. Assuming that the intrinsic spectrum is described by a single power law up to 20 TeV, a tight upper bound on the extragalactic background light intensity is obtained. A strong VHE flare lasting 8 days, with a rise time of ${\tau }_{r}^{\mathrm{rise}}=1.05\pm 0.49$ days and decay time of ${\tau }_{d}^{\mathrm{decay}}=2.17\pm 0.58$ days, was found in early 2022. A possible GeV flare is seen also in Fermi Large Area Telescope data during the VHE flare period. The variability time as short as 1 day seen in the LHAASO data suggests a compact emission region with a size of ∼3 × 10 ^15 δ cm ( δ being the Doppler factor of the emitting region), corresponding to a few Schwarzschild radii of the central supermassive black hole in M87. The continuous monitoring of the source reveals a duty cycle of ∼1% for VHE flares with a flux above 10 ^−11 erg cm ^−2 s ^−1 .

Published
2024
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2. Discovery of Very High Energy Gamma-Ray Emissions from the Low-luminosity AGN NGC 4278 by LHAASO

Author

Zhen Cao, F. Aharonian, Axikegu, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, W. Bian, A. V. Bukevich, Q. Cao, W. Y. Cao, Zhe Cao, J. Chang, J. F. Chang, A. M. Chen, E. S. Chen, H. X. Chen, Liang Chen, Lin Chen, Long Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, M. Y. Cui, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, Danzengluobu, X. Q. Dong, K. K. Duan, J. H. Fan, Y. Z. Fan, J. Fang, J. H. Fang, K. Fang, C. F. Feng, H. Feng, L. Feng, S. H. Feng, X. T. Feng, Y. Feng, Y. L. Feng, S. Gabici, B. Gao, C. D. Gao, Q. Gao, W. Gao, W. K. Gao, M. M. Ge, L. S. Geng, G. Giacinti, G. H. Gong, Q. B. Gou, M. H. Gu, F. L. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, M. Hasan, H. H. He, H. N. He, J. Y. He, Y. He, Y. K. Hor, B. W. Hou, C. Hou, X. Hou, H. B. Hu, Q. Hu, S. C. Hu, D. H. Huang, T. Q. Huang, W. J. Huang, X. T. Huang, X. Y. Huang, Y. Huang, X. L. Ji, H. Y. Jia, K. Jia, K. Jiang, X. W. Jiang, Z. J. Jiang, M. Jin, M. M. Kang, I. Karpikov, D. Kuleshov, K. Kurinov, B. B. Li, C. M. Li, Cheng Li, Cong Li, D. Li, F. Li, H. B. Li, H. C. Li, Jian Li, Jie Li, K. Li, S. D. Li, W. L. Li, X. R. Li, Xin Li, Y. Z. Li, Zhe Li, Zhuo Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, D. B. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. Liu, Y. N. Liu, Q. Luo, Y. Luo, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, Z. Min, W. Mitthumsiri, H. J. Mu, Y. C. Nan, A. Neronov, L. J. Ou, P. Pattarakijwanich, Z. Y. Pei, J. C. Qi, M. Y. Qi, B. Q. Qiao, J. J. Qin, A. Raza, D. Ruffolo, A. Sáiz, M. Saeed, D. Semikoz, L. Shao, O. Shchegolev, X. D. Sheng, F. W. Shu, H. C. Song, Yu. V. Stenkin, V. Stepanov, Y. Su, D. X. Sun, Q. N. Sun, X. N. Sun, Z. B. Sun, J. Takata, P. H. T. Tam, Q. W. Tang, R. Tang, Z. B. Tang, W. W. Tian, C. Wang, C. B. Wang, G. W. Wang, H. G. Wang, H. H. Wang, J. C. Wang, Kai Wang, L. P. Wang, L. Y. Wang, P. H. Wang, R. Wang, W. Wang, X. G. Wang, X. Y. Wang, Y. Wang, Y. D. Wang, Y. J. Wang, Z. H. Wang, Z. X. Wang, Zhen Wang, Zheng Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, Q. W. Wu, S. Wu, X. F. Wu, Y. S. Wu, S. Q. Xi, J. Xia, G. M. Xiang, D. X. Xiao, G. Xiao, Y. L. Xin, Y. Xing, D. R. Xiong, Z. Xiong, D. L. Xu, R. F. Xu, R. X. Xu, W. L. Xu, L. Xue, D. H. Yan, J. Z. Yan, T. Yan, C. W. Yang, C. Y. Yang, F. Yang, F. F. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, W. X. Yang, Y. H. Yao, Z. G. Yao, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. Yue, H. D. Zeng, T. X. Zeng, W. Zeng, M. Zha, B. B. Zhang, F. Zhang, H. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, Li Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. B. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. F. Zhang, Yi Zhang, Yong Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, X. H. Zhao, F. Zheng, W. J. Zhong, B. Zhou, H. Zhou, J. N. Zhou, M. Zhou, P. Zhou, R. Zhou, X. X. Zhou, B. Y. Zhu, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, Y. C. Zou, X. Zuo, and The LHAASO Collaboration

Subjects
High energy astrophysics, Gamma-ray astronomy, Low-luminosity active galactic nuclei, LINER galaxies, Blazars, Fanaroff-Riley radio galaxies, Astrophysics, QB460-466
Abstract

The first source catalog of the Large High Altitude Air Shower Observatory (LHAASO) reported the detection of a very high energy gamma-ray source, 1LHAASO J1219+2915. This Letter presents a further detailed study of the spectral and temporal behavior of this pointlike source. The best-fit position of the TeV source (R.A. = 185.°05 ± 0.°04, decl. = 29.°25 ± 0.°03) is compatible with NGC 4278 within ∼0.°03. Variation analysis shows an indication of variability on a timescale of a few months in the TeV band, which is consistent with low-frequency observations. Based on these observations, we report the detection of TeV γ -ray emissions from this low-luminosity active galactic nucleus. The observation by LHAASO's Water Cherenkov Detector Array during the active period has a significance level of 8.8 σ with a best-fit photon spectral index Γ = 2.56 ± 0.14 and a flux f _1–10 TeV = (7.0 ± 1.1 _sta ± 0.35 _syst ) × 10 ^−13 photons cm ^−2 s ^−1 , or approximately 5% of the Crab Nebula. The discovery of VHE gamma-ray emission from NGC 4278 indicates that compact, weak radio jets can efficiently accelerate particles and emit TeV photons.

Published
2024
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3. The First LHAASO Catalog of Gamma-Ray Sources

Author

Zhen Cao, F. Aharonian, Q. An, Axikegu, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, J. T. Cai, Q. Cao, W. Y. Cao, Zhe Cao, J. Chang, J. F. Chang, A. M. Chen, E. S. Chen, Liang Chen, Lin Chen, Long Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, M. Y. Cui, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, Danzengluobu, D. della Volpe, X. Q. Dong, K. K. Duan, J. H. Fan, Y. Z. Fan, J. Fang, K. Fang, C. F. Feng, L. Feng, S. H. Feng, X. T. Feng, Y. L. Feng, S. Gabici, B. Gao, C. D. Gao, L. Q. Gao, Q. Gao, W. Gao, W. K. Gao, M. M. Ge, L. S. Geng, G. Giacinti, G. H. Gong, Q. B. Gou, M. H. Gu, F. L. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, H. H. He, H. N. He, J. Y. He, X. B. He, Y. He, M. Heller, Y. K. Hor, B. W. Hou, C. Hou, X. Hou, H. B. Hu, Q. Hu, S. C. Hu, D. H. Huang, T. Q. Huang, W. J. Huang, X. T. Huang, X. Y. Huang, Y. Huang, Z. C. Huang, X. L. Ji, H. Y. Jia, K. Jia, K. Jiang, X. W. Jiang, Z. J. Jiang, M. Jin, M. M. Kang, T. Ke, D. Kuleshov, K. Kurinov, B. B. Li, Cheng Li, Cong Li, D. Li, F. Li, H. B. Li, H. C. Li, H. Y. Li, J. Li, Jian Li, Jie Li, K. Li, W. L. Li, X. R. Li, Xin Li, Y. Z. Li, Zhe Li, Zhuo Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, J. Y. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. Liu, Y. N. Liu, R. Lu, Q. Luo, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, Z. Min, W. Mitthumsiri, H. J. Mu, Y. C. Nan, A. Neronov, Z. W. Ou, B. Y. Pang, P. Pattarakijwanich, Z. Y. Pei, M. Y. Qi, Y. Q. Qi, B. Q. Qiao, J. J. Qin, D. Ruffolo, A. Sáiz, D. Semikoz, C. Y. Shao, L. Shao, O. Shchegolev, X. D. Sheng, F. W. Shu, H. C. Song, Yu. V. Stenkin, V. Stepanov, Y. Su, Q. N. Sun, X. N. Sun, Z. B. Sun, P. H. T. Tam, Q. W. Tang, Z. B. Tang, W. W. Tian, C. Wang, C. B. Wang, G. W. Wang, H. G. Wang, H. H. Wang, J. C. Wang, K. Wang, L. P. Wang, L. Y. Wang, P. H. Wang, R. Wang, W. Wang, X. G. Wang, X. Y. Wang, Y. Wang, Y. D. Wang, Y. J. Wang, Z. H. Wang, Z. X. Wang, Zhen Wang, Zheng Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, S. Wu, X. F. Wu, Y. S. Wu, S. Q. Xi, J. Xia, J. J. Xia, G. M. Xiang, D. X. Xiao, G. Xiao, G. G. Xin, Y. L. Xin, Y. Xing, Z. Xiong, D. L. Xu, R. F. Xu, R. X. Xu, W. L. Xu, L. Xue, D. H. Yan, J. Z. Yan, T. Yan, C. W. Yang, F. Yang, F. F. Yang, H. W. Yang, J. Y. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, S. B. Yang, Y. H. Yao, Z. G. Yao, Y. M. Ye, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. Yue, H. D. Zeng, T. X. Zeng, W. Zeng, M. Zha, B. B. Zhang, F. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, L. X. Zhang, Li Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. B. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. F. Zhang, Yi Zhang, Yong Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, F. Zheng, B. Zhou, H. Zhou, J. N. Zhou, M. Zhou, P. Zhou, R. Zhou, X. X. Zhou, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, X. Zuo, and (The LHAASO Collaboration)

Subjects
Gamma-ray astronomy, Gamma-ray observatories, Catalogs, Astrophysics, QB460-466
Abstract

We present the first catalog of very-high-energy and ultra-high-energy gamma-ray sources detected by the Large High Altitude Air Shower Observatory. The catalog was compiled using 508 days of data collected by the Water Cherenkov Detector Array from 2021 March to 2022 September and 933 days of data recorded by the Kilometer Squared Array from 2020 January to 2022 September. This catalog represents the main result from the most sensitive large coverage gamma-ray survey of the sky above 1 TeV, covering decl. from −20° to 80°. In total, the catalog contains 90 sources with an extended size smaller than 2° and a significance of detection at >5 σ . Based on our source association criteria, 32 new TeV sources are proposed in this study. Among the 90 sources, 43 sources are detected with ultra-high energy ( E > 100 TeV) emission at >4 σ significance level. We provide the position, extension, and spectral characteristics of all the sources in this catalog.

Published
2024
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4. Construction and on-site performance of the LHAASO WFCTA camera

Author

F. Aharonian, Q. An, Axikegu, L. X. Bai, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, H. Cai, J. T. Cai, Z. Cao, J. Chang, J. F. Chang, X. C. Chang, B. M. Chen, J. Chen, L. Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, X. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, Danzengluobu, D. della Volpe, B. D’Ettorre Piazzoli, X. J. Dong, J. H. Fan, Y. Z. Fan, Z. X. Fan, J. Fang, K. Fang, C. F. Feng, L. Feng, S. H. Feng, Y. L. Feng, B. Gao, C. D. Gao, Q. Gao, W. Gao, M. M. Ge, L. S. Geng, G. H. Gong, Q. B. Gou, M. H. Gu, J. G. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, H. H. He, H. N. He, J. C. He, S. L. He, X. B. He, Y. He, M. Heller, Y. K. Hor, C. Hou, X. Hou, H. B. Hu, S. Hu, S. C. Hu, X. J. Hu, D. H. Huang, Q. L. Huang, W. H. Huang, X. T. Huang, Z. C. Huang, F. Ji, X. L. Ji, H. Y. Jia, K. Jiang, Z. J. Jiang, C. Jin, D. Kuleshov, K. Levochkin, B. B. Li, C. Li, F. Li, H. B. Li, H. C. Li, H. Y. Li, J. Li, K. Li, W. L. Li, X. Li, X. R. Li, Y. Li, Y. Z. Li, Z. Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, J. S. Liu, J. Y. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. N. Liu, Z. X. Liu, W. J. Long, R. Lu, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, A. Masood, W. Mitthumsiri, T. Montaruli, Y. C. Nan, B. Y. Pang, P. Pattarakijwanich, Z. Y. Pei, M. Y. Qi, D. Ruffolo, V. Rulev, A. Sáiz, L. Shao, O. Shchegolev, X. D. Sheng, J. R. Shi, H. C. Song, Yu. V. Stenkin, V. Stepanov, Q. N. Sun, X. N. Sun, Z. B. Sun, P. H. T. Tam, Z. B. Tang, W. W. Tian, B. D. Wang, C. Wang, H. Wang, H. G. Wang, J. C. Wang, J. S. Wang, L. P. Wang, L. Y. Wang, R. N. Wang, W. Wang, X. G. Wang, X. J. Wang, X. Y. Wang, Y. D. Wang, Y. J. Wang, Y. P. Wang, Z. Wang, Z. H. Wang, Z. X. Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, S. Wu, W. X. Wu, X. F. Wu, S. Q. Xi, J. Xia, J. J. Xia, G. M. Xiang, G. Xiao, H. B. Xiao, G. G. Xin, Y. L. Xin, Y. Xing, D. L. Xu, R. X. Xu, L. Xue, D. H. Yan, C. W. Yang, F. F. Yang, J. Y. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, S. B. Yang, Y. H. Yao, Z. G. Yao, Y. M. Ye, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. D. Zeng, T. X. Zeng, W. Zeng, Z. K. Zeng, M. Zha, X. X. Zhai, B. B. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, J. W. Zhang, L. Zhang, L. X. Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. R. Zhang, S S. Zhang, X. Zhang, X. P. Zhang, Y. Zhang, Y. F. Zhang, Y. L. Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, F. Zheng, Y. Zheng, B. Zhou, H. Zhou, J. N. Zhou, P. Zhou, R. Zhou, X. X. Zhou, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, X. Zuo, and The LHAASO Collaboration

Subjects
Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract The focal plane camera is the core component of the Wide Field-of-view Cherenkov/fluorescence Telescope Array (WFCTA) of the Large High-Altitude Air Shower Observatory (LHAASO). Because of the capability of working under moonlight without aging, silicon photomultipliers (SiPM) have been proven to be not only an alternative but also an improvement to conventional photomultiplier tubes (PMT) in this application. Eighteen SiPM-based cameras with square light funnels have been built for WFCTA. The telescopes have collected more than 100 million cosmic ray events and preliminary results indicate that these cameras are capable of working under moonlight. The characteristics of the light funnels and SiPMs pose challenges (e.g. dynamic range, dark count rate, assembly techniques). In this paper, we present the design features, manufacturing techniques and performances of these cameras. Finally, the test facilities, the test methods and results of SiPMs in the cameras are reported here.

Published
2021
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5. Line-of-shower trigger method to lower energy threshold for GRB detection using LHAASO-WCDA

Author

C. F. Feng, Bin Zhou, X. L. Ji, R. Lu, H. B. Xiao, J. R. Shi, W. Zeng, Z. H. Wang, Shengxue Zhang, Pak-Hin Thomas Tam, H. C. Li, Jun Liu, H. Y. Jia, B. D'Ettorre Piazzoli, W. X. Wu, Junjie Mao, Y. Q. Guo, Dong Liu, F. Ji, H. R. Wu, Y. J. Wei, Alejandro Sáiz, Oleg Shchegolev, L. Feng, V. Rulev, L. Xue, Xuliang Chen, Xing-Yuan Hou, D. M. Wei, S. Hu, M. L. Chen, Jianeng Zhou, J. Y. Liu, Warit Mitthumsiri, Y. Zhang, Q. An, Y. He, Q. Gao, Ruizhi Yang, X. N. Sun, H. B. Hu, H. Liu, L. Chen, X. G. Wang, S. Q. Xi, J. Fang, X. H. You, Ping Zhou, Z. C. Huang, Y. Z. Li, P. F. Zhang, C. Y. Wu, Hong-Guang Wang, G. M. Xiang, W. Liu, Yu-Lei Chen, Zihuang Cao, X. C. Chang, Z. K. Zeng, Y. J. Bi, H. D. Liu, Y. D. Cheng, Bo Zhang, Y. Zheng, L. Q. Yin, Duo Yan, F. Zheng, Hao Zhou, X. X. Zhou, Q. Yuan, Hefan Li, J. F. Chang, Z. X. Liu, Felix Aharonian, H. N. He, C. D. Gao, Lei Zhao, Q. H. Chen, Youping Li, Y. M. Ye, B. B. Li, Yongchun Wang, Y. D. Cui, Bai Yibing, L. P. Wang, J. B. Zhao, Y. J. Wang, J. Y. Yang, S. Z. Chen, Yunchao Liu, B. Z. Dai, Rong Xu, Z. X. Fan, Z. Y. You, Z. G. Dai, X. F. Wu, He Zhang, S. H. Feng, S. B. Yang, J. J. Xia, W. Gao, S. L. He, Y. P. Wang, B. M. Chen, Fan Yang, A. Masood, Kun Fang, S.H. Chen, Yugang Zhang, H. Cai, Lang Shao, H. Wang, J.W. Xia, L. Z. Zhao, G. C. Xiao, X. X. Zhai, Y. C. Nan, Shi-Qi Hu, X. J. Bi, Z. Li, R. Liu, E. W. Liang, X. Zuo, M. J. Yang, Y. H. Yao, W. L. Li, L. X. Zhang, H. K. Lv, Xufang Li, B. Y. Pang, Zebo Tang, M. H. Gu, Z. Y. Pei, Xuejiao Li, F. R. Zhu, T. L. Chen, Qie Sun, K. J. Zhu, Ying Zhang, H. M. Zhang, J. Chen, H. L. Dai, Y. L. Xin, T. Wen, S. W. Cui, M. Zha, J. C. He, W. H. Huang, L. X. Bai, Binyu Zhao, Yun-Feng Liang, Jixia Li, X. H. Cui, Xinbo He, K. Jiang, X. J. Hu, J. W. Zhang, Li-Sheng Geng, Wenwu Tian, Z. X. Wang, Xiaofei Zhang, David Ruffolo, Yu. V. Stenkin, C. Hou, Z. B. Sun, Shuibin Lin, Lu Zhang, K. Levochkin, Cheng Guang Zhu, X. D. Sheng, Minghao Qi, Houdun Zeng, Jun-Jie Wei, Jia Zhang, Y. A. Han, H. B. Li, Danzengluobu, Rui Zhang, H. C. Song, Linbin Yang, Y. Z. Fan, J. T. Cai, H. H. He, Y. M. Xing, F. Y. Li, D. H. Huang, H. Zhu, Xiang Zhang, M. M. Ge, J. G. Guo, S. R. Zhang, N. Cheng, L. L. Ma, G. H. Gong, J. S. Wang, Cunguo Wang, Shujuan Liu, N. Yin, Y. H. Yu, W. J. Long, Axikegu, Xuelong Wang, P. P. Zhang, Chunlong Li, Minghui Liu, D. Bastieri, Jinyao Liu, Z. G. Yao, X. H. Ma, M. Heller, K. Li, Z. J. Jiang, J. Liu, R. N. Wang, V. I. Stepanov, Jian Wang, Chiming Jin, D.A. Kuleshov, G. G. Xin, M. J. Chen, S. P. Zhao, Y. Y. Guo, Donglian Xu, X. L. Guo, X. J. Dong, Y. K. Hor, T. Montaruli, Y. L. Feng, W. Wang, P. Pattarakijwanich, S. Wu, B. D. Wang, C. X. Liu, Y. W. Bao, X. T. Huang, R. Zhou, L. Y. Wang, D. della Volpe, C. W. Yang, Jun-Hui Fan, Zujian Wang, Q. B. Gou, Qizhi Huang, B. Liu, Bingshui Gao, Xiang-Yu Wang, Tao Zeng, and Bin Ma

Subjects
Physics, Nuclear and High Energy Physics, Cherenkov detector, Astrophysics::High Energy Astrophysical Phenomena, Detector, Astrophysics, law.invention, Air shower, Nuclear Energy and Engineering, Duty cycle, law, Observatory, Gamma-ray burst, Energy (signal processing), Line (formation)
Abstract

Observation of high energy and very high emission from Gamma Ray Bursts (GRBs) is crucial to study the gigantic explosion and the underline processes. With a large field-of-view and almost full duty cycle, the Water Cherenkov Detector Array (WCDA), a sub-array of the Large High Altitude Air Shower Observatory (LHAASO), is appropriate to monitor the very high energy emission from unpredictable transients such as GRBs. Nevertheless, the main issue for an extensive air shower array is the high energy threshold which limits the horizon of the detector. To address this issue a new trigger method is developed in this article to lower the energy threshold of WCDA for GRB observation. The proposed method significantly improves the detection efficiency of WCDA for gamma-rays around the GRB direction at 10-300 GeV. The sensitivity of the WCDA for GRB detection with the new trigger method is estimated. The achieved sensitivity of the quarter WCDA array above 10 GeV is comparable with that of Fermi-LAT. The data analysis process and corresponding fluence upper limit for GRB 190719C is presented as an example.

Published
2021

6. A dynamic range extension system for LHAASO WCDA-1

Author

F. Aharonian, Q. An, null Axikegu, L. X. Bai, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, H. Cai, J. T. Cai, Z. Cao, J. Chang, J. F. Chang, X. C. Chang, B. M. Chen, J. Chen, L. Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, X. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, null Danzengluobu, D. della Volpe, B. D’Ettorre Piazzoli, X. J. Dong, J. H. Fan, Y. Z. Fan, Z. X. Fan, J. Fang, K. Fang, C. F. Feng, L. Feng, S. H. Feng, Y. L. Feng, B. Gao, C. D. Gao, Q. Gao, W. Gao, M. M. Ge, L. S. Geng, G. H. Gong, Q. B. Gou, M. H. Gu, J. G. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, H. H. He, H. N. He, J. C. He, S. L. He, X. B. He, Y. He, M. Heller, Y. K. Hor, C. Hou, X. Hou, H. B. Hu, S. Hu, S. C. Hu, X. J. Hu, D. H. Huang, Q. L. Huang, W. H. Huang, X. T. Huang, Y. Huang, Z. C. Huang, F. Ji, X. L. Ji, H. Y. Jia, K. Jiang, Z. J. Jiang, C. Jin, D. Kuleshov, K. Levochkin, B. B. Li, C. Li, F. Li, H. B. Li, H. C. Li, H. Y. Li, J. Li, K. Li, W. L. Li, X. Li, X. R. Li, Y. Li, Y. Z. Li, Z. Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, J. S. Liu, J. Y. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. N. Liu, Z. X. Liu, W. J. Long, R. Lu, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, A. Masood, W. Mitthumsiri, T. Montaruli, Y. C. Nan, B. Y. Pang, P. Pattarakijwanich, Z. Y. Pei, M. Y. Qi, D. Ruffolo, V. Rulev, A. Sáiz, L. Shao, O. Shchegolev, X. D. Sheng, J. R. Shi, H. C. Song, Yu. V. Stenkin, V. Stepanov, Q. N. Sun, X. N. Sun, Z. B. Sun, P. H. T. Tam, Z. B. Tang, W. W. Tian, B. D. Wang, C. Wang, H. Wang, H. G. Wang, J. C. Wang, J. S. Wang, L. P. Wang, L. Y. Wang, R. N. Wang, W. Wang, X. G. Wang, X. J. Wang, X. Y. Wang, Y. D. Wang, Y. J. Wang, Y. P. Wang, Z. Wang, Z. H. Wang, Z. X. Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, S. Wu, W. X. Wu, X. F. Wu, S. Q. Xi, J. Xia, J. J. Xia, G. M. Xiang, G. Xiao, H. B. Xiao, G. G. Xin, Y. L. Xin, Y. Xing, D. L. Xu, R. X. Xu, L. Xue, D. H. Yan, C. W. Yang, F. F. Yang, J. Y. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, S. B. Yang, Y. H. Yao, Z. G. Yao, Y. M. Ye, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. D. Zeng, T. X. Zeng, W. Zeng, Z. K. Zeng, M. Zha, X. X. Zhai, B. B. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, J. W. Zhang, L. Zhang, L. X. Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. Zhang, Y. F. Zhang, Y. L. Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, F. Zheng, Y. Zheng, B. Zhou, H. Zhou, J. N. Zhou, P. Zhou, R. Zhou, X. X. Zhou, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, and X. Zuo

Subjects
Physics, Nuclear and High Energy Physics, Physics::Instrumentation and Detectors, Dynamic range, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Cosmic ray, Extension (predicate logic), Measure (mathematics), Effective nuclear charge, Nuclear physics, Air shower, Nuclear Energy and Engineering, Orders of magnitude (time), Energy (signal processing)
Abstract

The main scientific goal of LHAASO-WCDA is to survey gamma-ray sources with energy from 100 GeV to 30 TeV. To observe high-energy shower events, especially to measure the energy spectrum of cosmic rays from 100 TeV to 10 PeV, a dynamic range extension system (WCDA++) is designed to use a 1.5-inch PMT with a dynamic range of four orders of magnitude for each cell in WCDA-1. The dynamic range is extended by using these PMTs to measure the effective charge density in the core region of air shower events, which is an important parameter for identifying the composition of primary particles. The system has been running for more than one year. In this paper, the details of the design and performance of WCDA++ are presented.

Published
2021

7. Constraints on heavy decaying dark matter from 570 days of LHAASO observations

Author

Zhen, Cao, F, Aharonian, Q, An, Axikegu, L X, Bai, Y X, Bai, Y W, Bao, D, Bastieri, X J, Bi, Y J, Bi, J T, Cai, Zhe, Cao, J, Chang, J F, Chang, E S, Chen, Liang, Chen, Long, Chen, M J, Chen, M L, Chen, Q H, Chen, S H, Chen, S Z, Chen, T L, Chen, Y, Chen, H L, Cheng, N, Cheng, Y D, Cheng, S W, Cui, X H, Cui, Y D, Cui, B, D'Ettorre Piazzoli, B Z, Dai, H L, Dai, Z G, Dai, Danzengluobu, D, Della Volpe, K K, Duan, J H, Fan, Y Z, Fan, Z X, Fan, J, Fang, K, Fang, C F, Feng, L, Feng, S H, Feng, X T, Feng, Y L, Feng, B, Gao, C D, Gao, L Q, Gao, Q, Gao, W, Gao, W K, Gao, M M, Ge, L S, Geng, G H, Gong, Q B, Gou, M H, Gu, F L, Guo, J G, Guo, X L, Guo, Y Q, Guo, Y Y, Guo, Y A, Han, H H, He, H N, He, S L, He, X B, He, Y, He, M, Heller, Y K, Hor, C, Hou, X, Hou, H B, Hu, Q, Hu, S, Hu, S C, Hu, X J, Hu, D H, Huang, W H, Huang, X T, Huang, X Y, Huang, Y, Huang, Z C, Huang, X L, Ji, H Y, Jia, K, Jia, K, Jiang, Z J, Jiang, M, Jin, M M, Kang, T, Ke, D, Kuleshov, K, Levochkin, B B, Li, Cheng, Li, Cong, Li, F, Li, H B, Li, H C, Li, H Y, Li, J, Li, Jian, Li, Jie, Li, K, Li, W L, Li, X R, Li, Xin, Li, Y Z, Li, Zhe, Li, Zhuo, Li, E W, Liang, Y F, Liang, S J, Lin, B, Liu, C, Liu, D, Liu, H, Liu, H D, Liu, J, Liu, J L, Liu, J S, Liu, J Y, Liu, M Y, Liu, R Y, Liu, S M, Liu, W, Liu, Y, Liu, Y N, Liu, W J, Long, R, Lu, Q, Luo, H K, Lv, B Q, Ma, L L, Ma, X H, Ma, J R, Mao, A, Masood, Z, Min, W, Mitthumsiri, Y C, Nan, Z W, Ou, B Y, Pang, P, Pattarakijwanich, Z Y, Pei, M Y, Qi, Y Q, Qi, B Q, Qiao, J J, Qin, D, Ruffolo, A, Sáiz, C Y, Shao, L, Shao, O, Shchegolev, X D, Sheng, J Y, Shi, H C, Song, Yu V, Stenkin, V, Stepanov, Y, Su, Q N, Sun, X N, Sun, Z B, Sun, P H T, Tam, Z B, Tang, W W, Tian, B D, Wang, C, Wang, H, Wang, H G, Wang, J C, Wang, J S, Wang, L P, Wang, L Y, Wang, R, Wang, R N, Wang, W, Wang, X G, Wang, X Y, Wang, Y, Wang, Y D, Wang, Y J, Wang, Y P, Wang, Z H, Wang, Z X, Wang, Zhen, Wang, Zheng, Wang, D M, Wei, J J, Wei, Y J, Wei, T, Wen, C Y, Wu, H R, Wu, S, Wu, X F, Wu, Y S, Wu, S Q, Xi, J, Xia, J J, Xia, G M, Xiang, D X, Xiao, G, Xiao, G G, Xin, Y L, Xin, Y, Xing, Z, Xiong, D L, Xu, R X, Xu, L, Xue, D H, Yan, J Z, Yan, C W, Yang, F F, Yang, H W, Yang, J Y, Yang, L L, Yang, M J, Yang, R Z, Yang, S B, Yang, Y H, Yao, Z G, Yao, Y M, Ye, L Q, Yin, N, Yin, X H, You, Z Y, You, Y H, Yu, Q, Yuan, H, Yue, H D, Zeng, T X, Zeng, W, Zeng, Z K, Zeng, M, Zha, X X, Zhai, B B, Zhang, F, Zhang, H M, Zhang, H Y, Zhang, J L, Zhang, L X, Zhang, Li, Zhang, Lu, Zhang, P F, Zhang, P P, Zhang, R, Zhang, S B, Zhang, S R, Zhang, S S, Zhang, X, Zhang, X P, Zhang, Y F, Zhang, Y L, Zhang, Yi, Zhang, Yong, Zhang, B, Zhao, J, Zhao, L, Zhao, L Z, Zhao, S P, Zhao, F, Zheng, Y, Zheng, B, Zhou, H, Zhou, J N, Zhou, P, Zhou, R, Zhou, X X, Zhou, C G, Zhu, F R, Zhu, H, Zhu, K J, Zhu, X, Zuo, S, Ando, M, Chianese, D F G, Fiorillo, G, Miele, K C Y, Ng, and GRAPPA (ITFA, IoP, FNWI)

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), High Energy Physics - Phenomenology, Cosmology and Nongalactic Astrophysics (astro-ph.CO), High Energy Physics - Phenomenology (hep-ph), General Physics and Astronomy, FOS: Physical sciences, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern γ-ray sky at energies above 10 TeV with unprecedented sensitivity. γ-ray observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after γ/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest γ-ray constraints on the lifetime of heavy dark matter particles with mass between 105 and 109 GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.

Published
2022

8. Ultrahigh-energy photons up to 1.4 petaelectronvolts from 12 γ-ray Galactic sources

Author

Alejandro Sáiz, Y. H. Yao, W. X. Wu, P. P. Zhang, Zhuo Li, R. Liu, Pak-Hin Thomas Tam, H. C. Li, Liang Chen, J. C. Wang, Y. L. Xin, L. Chen, M. J. Chen, Hong-Guang Wang, Y. J. Wei, S. Hu, Junjie Mao, Y. Q. Guo, J. Y. Liu, V. Rulev, P. F. Zhang, L. Xue, H. B. Hu, H. Liu, Rui Zhang, Linbin Yang, C. F. Feng, F. Ji, Xiaofei Zhang, F. Zheng, V. I. Stepanov, Ping Zhou, Q. H. Chen, H. R. Wu, Warit Mitthumsiri, X. C. Chang, Z. K. Zeng, C. D. Gao, Bin Zhou, W. L. Li, S. Z. Chen, M. M. Ge, Lei Zhao, Y. Z. Li, Y. Y. Guo, Y. J. Bi, Zhe Cao, Y. K. Hor, Xuejiao Li, H. D. Liu, S. H. Feng, B. Liu, Y. D. Cheng, Bo Zhang, H. K. Lv, H. M. Zhang, K. Levochkin, Y. J. Wang, L. X. Bai, Jixia Li, T. Montaruli, Duo Yan, Hefan Li, Ying Zhang, Bingshui Gao, Q. An, H. B. Xiao, J. R. Shi, X. D. Sheng, Z. X. Liu, W. H. Huang, M. L. Chen, Jianeng Zhou, Q. Gao, Minghao Qi, W. Zeng, Li-Sheng Geng, J. Chen, B. M. Chen, T. Wen, S. W. Cui, Z. X. Wang, Chiming Jin, S. B. Yang, L. Z. Zhao, C. W. Yang, J. B. Zhao, D.A. Kuleshov, Y. M. Xing, L. P. Wang, E. W. Liang, X. F. Wu, Zhe Li, B. Y. Pang, B. B. Li, X. Zuo, Cong Li, S. Q. Xi, Kun Fang, W. Gao, B. Z. Dai, Z. H. Wang, H. Cai, Jun Liu, Zhen Wang, J. C. He, Houdun Zeng, J. Fang, G. C. Xiao, Y. C. Nan, Z. G. Yao, Z. Y. Pei, Jun-Hui Fan, X. X. Zhou, Q. Yuan, H. B. Li, Shi-Qi Hu, G. G. Xin, J. F. Chang, Xufang Li, Oleg Shchegolev, G. M. Xiang, S. P. Zhao, W. Liu, X. L. Ji, M. J. Yang, H. H. He, R. Lu, Zhengguo Cao, Felix Aharonian, J. W. Zhang, H. C. Song, Yongchun Wang, Yugang Zhang, Wenwu Tian, He Zhang, Bai Yibing, S. L. He, Donglian Xu, Y. L. Feng, Zebo Tang, X. L. Guo, Y. D. Cui, X. J. Dong, Zheng Wang, Jun-Jie Wei, Q. B. Gou, Qizhi Huang, H. N. He, K. J. Zhu, M. Zha, B. D. Wang, Ruizhi Yang, X. N. Sun, Y. P. Wang, Z. C. Huang, H. L. Dai, H. Wang, Xiang Zhang, Xing-Yuan Hou, Yunchao Liu, H. Y. Jia, D. M. Wei, Z. G. Dai, Rong Xu, Fan Yang, A. Masood, F. Y. Li, Xinbo He, Youping Li, X. T. Huang, L. Y. Wang, X. R. Li, J. J. Xia, K. Jiang, Binyu Zhao, X. J. Hu, Yun-Feng Liang, W. Wang, Y. A. Han, J. G. Guo, Yu. V. Stenkin, Lang Shao, J.W. Xia, P. Pattarakijwanich, X. H. You, S.H. Chen, S. R. Zhang, C. Hou, Shuibin Lin, Lu Zhang, L. Feng, Xuelong Wang, S. Wu, X. X. Zhai, Xuliang Chen, C. X. Liu, L. L. Ma, Y. He, Z. X. Fan, Z. Y. You, F. R. Zhu, Y. W. Bao, Qie Sun, Yi Chen, X. G. Wang, Yi Zhang, Xiang-Yu Wang, D. H. Huang, R. Zhou, Hao Zhou, H. Zhu, X. J. Bi, D. della Volpe, Tao Zeng, T. L. Chen, Bin Ma, J. S. Wang, Cunguo Wang, L. X. Zhang, Shujuan Liu, N. Yin, N. Cheng, D. Bastieri, X. H. Cui, Cheng Li, W. J. Long, Shengxue Zhang, Axikegu, Li Zhang, G. H. Gong, Danzengluobu, M. H. Gu, Y. H. Yu, Jie Zhang, Y. Z. Fan, Dong Liu, C. Y. Wu, J. T. Cai, Long Chen, Y. Zheng, L. Q. Yin, Y. M. Ye, J. Y. Yang, B D Ettorre Piazzoli, David Ruffolo, Z. B. Sun, Cheng Guang Zhu, X. H. Ma, M. Heller, K. Li, Z. J. Jiang, J. Liu, Yong Zhang, Minghui Liu, R. N. Wang, and Jinyao Liu

Subjects
Physics, Multidisciplinary, Photon, COSMIC cancer database, Proton, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Electron, Astrophysics, 01 natural sciences, Galaxy, Supernova, Crab Nebula, Pulsar, 0103 physical sciences, 010306 general physics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

The extension of the cosmic-ray spectrum beyond 1 petaelectronvolt (PeV; 1015 electronvolts) indicates the existence of the so-called PeVatrons—cosmic-ray factories that accelerate particles to PeV energies. We need to locate and identify such objects to find the origin of Galactic cosmic rays1. The principal signature of both electron and proton PeVatrons is ultrahigh-energy (exceeding 100 TeV) γ radiation. Evidence of the presence of a proton PeVatron has been found in the Galactic Centre, according to the detection of a hard-spectrum radiation extending to 0.04 PeV (ref. 2). Although γ-rays with energies slightly higher than 0.1 PeV have been reported from a few objects in the Galactic plane3–6, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators. Observations of γ-rays with energies up to 1.4 PeV find that 12 sources in the Galaxy are PeVatrons, one of which is the Crab Nebula.

Published
2021

9. Discovery of a new $\gamma$-ray source LHAASO J0341+5258 with emission up to 200TeV

Author

Zhengguo Cao, L. Feng, Xufang Li, Zebo Tang, Jun-Jie Wei, C. Y. Wu, Jia Zhang, L. X. Bai, Yi Zhang, H. K. Lv, Jixia Li, L. L. Yang, Z. X. Wang, M. Zha, Y. M. Ye, X. H. Ma, L. P. Wang, X. G. Wang, Donglian Xu, X. L. Guo, Y. A. Han, Binyu Zhao, Yun-Feng Liang, Houdun Zeng, Zhe Li, Y. Su, B. Z. Dai, Z. G. Dai, Jinmei Liu, B. D'Ettorre Piazzoli, Z. G. Yao, Y. Zheng, W. X. Wu, M. L. Chen, Jianeng Zhou, Hefan Li, W. Wang, P. Pattarakijwanich, Rong Xu, J. J. Xia, X. X. Zhai, J. Fang, F. R. Zhu, Qie Sun, Yi Chen, H. B. Li, G. M. Xiang, W. Liu, B. Y. Pang, S. Wu, X. L. Ji, R. Lu, K. Li, Y. J. Bi, H. D. Liu, Y. D. Cheng, Bo Zhang, L. Q. Yin, Hanzhong Zhang, C. X. Liu, D. della Volpe, Y. D. Cui, Kun Fang, Yugang Zhang, E. W. Liang, Ping Zhou, Z. J. Jiang, Y. J. Wei, J. Liu, Yong Zhang, Duo Yan, Yu. V. Stenkin, S. L. He, Y. P. Wang, Z. X. Liu, D. H. Huang, R. N. Wang, S. M. Liu, F. Ji, V. Rulev, Y. Z. Li, H. H. He, H. Zhu, C. Hou, Zheng Wang, B. Q. Ma, Y. C. Nan, L. Xue, Jun Liu, Lu Zhang, H. Y. Jia, D. M. Wei, V. I. Stepanov, E. S. Chen, Sina Chen, K. J. Zhu, Y. Q. Qi, Fulai Guo, J. Y. Shi, Minghui Liu, Yi Liu, J. B. Zhao, H. Wang, X. F. Wu, Zhen Wang, Z. X. Fan, Z. Y. You, Shi-Qi Hu, J. Y. Yang, N. Cheng, Z. K. Zeng, C. D. Gao, X. H. You, Long Gao, H. C. Song, Lei Zhao, D.A. Kuleshov, X. X. Zhou, Q. Yuan, B. M. Chen, Ruizhi Yang, X. N. Sun, Shengxue Zhang, Danzengluobu, J. F. Chang, S. P. Zhao, H. Liu, J.W. Xia, W. Gao, G. C. Xiao, Felix Aharonian, Xinbo He, K. Jiang, Pak-Hin Thomas Tam, H. C. Li, Y. Wang, Y. Z. Fan, Dong Liu, Y. W. Bao, P. F. Zhang, X. J. Bi, H. N. He, T. L. Chen, L. Z. Zhao, X. J. Hu, R. Zhou, Ying Zhang, Oleg Shchegolev, Junjie Mao, Y. Q. Guo, F. Y. Li, K. Levochkin, J. T. Cai, X. D. Sheng, Cong Li, X. Zuo, B. B. Li, Long Chen, Yunchao Liu, H. L. Dai, T. Wen, S. W. Cui, S. Z. Chen, David Ruffolo, Y. M. Xing, H. R. Wu, Liang Chen, Xiang-Kun Dong, S. Hu, J. Y. Liu, X. Y. Huang, P. P. Zhang, X. H. Cui, Minghao Qi, Z. B. Sun, Y. Bai, Z. Y. Pei, Cheng Guang Zhu, Yuan-Hao Wang, Zhuo Li, Warit Mitthumsiri, H. M. Zhang, Q. An, Y. H. Yao, W. H. Huang, H. Zhou, W. J. Long, Binbin Zhou, Li-Sheng Geng, R. Liu, Xiang Zhang, J. G. Guo, J. W. Zhang, S. R. Zhang, Wenwu Tian, L. L. Ma, Q. Gao, C. F. Feng, Jiangang He, J. S. Wang, Cunguo Wang, Y. L. Xin, Z. C. Huang, H. B. Hu, N. Yin, B. Q. Qiao, Xin Li, Cheng Li, Jiajun Qin, M. H. Gu, Boyang Wang, Rui Zhang, H. B. Xiao, W. Zeng, L. X. Zhang, S. H. Feng, M. M. Ge, Axikegu, Yonggang Wang, M. J. Chen, Zhao-Qi Wang, Y. Y. Guo, Li Zhang, G. H. Gong, Zhe Cao, Y. K. Hor, Y. H. Yu, T. Montaruli, Jian Wang, Chiming Jin, Z. Min, Xuelong Wang, G. G. Xin, Kai-Kai Duan, D. Bastieri, Y. L. Feng, T. Ke, S. J. Lin, X. T. Huang, L. Y. Wang, B. Liu, Jingzhi Yan, Bingshui Gao, Xiang-Yu Wang, Yulong Li, Tao Zeng, Xuliang Chen, Y. He, C. W. Yang, Jun-Hui Fan, Q. B. Gou, W. L. Li, D. X. Xiao, Qizhi Huang, J. Chen, Xiao-Hu Zhang, H. Cai, M. J. Yang, S. Q. Xi, Hong-Guang Wang, Alejandro Sáiz, Q. H. Chen, S. B. Yang, Fan Yang, A. Masood, F. Zheng, Lang Shao, and M. Heller

Subjects
Physics, Astrophysics::High Energy Astrophysical Phenomena, Hadron, Gamma ray, Flux, Astronomy and Astrophysics, Astrophysics, Galactic plane, Crab Nebula, Pulsar, Space and Planetary Science, Angular diameter, High Energy Physics::Experiment, Supernova remnant, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::Galaxy Astrophysics
Abstract

We report the discovery of a new unidentified extended $\gamma$-ray source in the Galactic plane named LHAASO J0341+5258 with a pre-trial significance of 8.2 standard deviations above 25 TeV. The best fit position is R.A.$=55.34^{\circ}\pm0.11^{\circ}$ and Dec$=52.97^{\circ}\pm0.07^{\circ}$. The angular size of LHAASO J0341+5258 is $0.29^\circ \pm 0.06^\circ_{stat} \pm0.02^\circ_{sys}$. The flux above 25 TeV is about $20\%$ of the flux of Crab Nebula. Although a power-law fit of the spectrum from 10 TeV to 200 TeV with the photon index $\alpha=2.98 \pm 0.19_{stat} \pm 0.02_{sys}$ is not excluded, the LHAASO data together with the flux upper limit at 10 GeV set by the Fermi LAT observation, indicate a noticeable steepening of an initially hard power-law spectrum %($\alpha \leq 1.75$) spectrum with a cutoff at $\approx 50$ TeV. We briefly discuss the origin of UHE gamma-rays. The lack of an energetic pulsar and a young SNR inside or in the vicinity of LHAASO J0341+5258 challenge, but do not exclude both the leptonic and hadronic scenarios of gamma-ray production., Comment: Accepted by APJL

Published
2021

10. Exploring Lorentz Invariance Violation from Ultrahigh-Energy γ Rays Observed by LHAASO

Author

Zhen, Cao, F, Aharonian, Q, An, Axikegu, L X, Bai, Y X, Bai, Y W, Bao, D, Bastieri, X J, Bi, Y J, Bi, H, Cai, J T, Cai, Zhe, Cao, J, Chang, J F, Chang, B M, Chen, E S, Chen, J, Chen, Liang, Chen, Long, Chen, M J, Chen, M L, Chen, Q H, Chen, S H, Chen, S Z, Chen, T L, Chen, X L, Chen, Y, Chen, N, Cheng, Y D, Cheng, S W, Cui, X H, Cui, Y D, Cui, B D'Ettorre, Piazzoli, B Z, Dai, H L, Dai, Z G, Dai, Danzengluobu, D, Della Volpe, X J, Dong, K K, Duan, J H, Fan, Y Z, Fan, Z X, Fan, J, Fang, K, Fang, C F, Feng, L, Feng, S H, Feng, Y L, Feng, B, Gao, C D, Gao, L Q, Gao, Q, Gao, W, Gao, M M, Ge, L S, Geng, G H, Gong, Q B, Gou, M H, Gu, F L, Guo, J G, Guo, X L, Guo, Y Q, Guo, Y Y, Guo, Y A, Han, H H, He, H N, He, J C, He, S L, He, X B, He, Y, He, M, Heller, Y K, Hor, C, Hou, X, Hou, H B, Hu, S, Hu, S C, Hu, X J, Hu, D H, Huang, Q L, Huang, W H, Huang, X T, Huang, X Y, Huang, Z C, Huang, F, Ji, X L, Ji, H Y, Jia, K, Jiang, Z J, Jiang, C, Jin, T, Ke, D, Kuleshov, K, Levochkin, B B, Li, Cheng, Li, Cong, Li, F, Li, H B, Li, H C, Li, H Y, Li, Jian, Li, Jie, Li, K, Li, W L, Li, X R, Li, Xin, Li, Y, Li, Y Z, Li, Zhe, Li, Zhuo, Li, E W, Liang, Y F, Liang, S J, Lin, B, Liu, C, Liu, D, Liu, H, Liu, H D, Liu, J, Liu, J L, Liu, J S, Liu, J Y, Liu, M Y, Liu, R Y, Liu, S M, Liu, W, Liu, Y, Liu, Y N, Liu, Z X, Liu, W J, Long, R, Lu, H K, Lv, B Q, Ma, L L, Ma, X H, Ma, J R, Mao, A, Masood, Z, Min, W, Mitthumsiri, T, Montaruli, Y C, Nan, B Y, Pang, P, Pattarakijwanich, Z Y, Pei, M Y, Qi, Y Q, Qi, B Q, Qiao, J J, Qin, D, Ruffolo, V, Rulev, A, Sáiz, L, Shao, O, Shchegolev, X D, Sheng, J R, Shi, H C, Song, Yu V, Stenkin, V, Stepanov, Y, Su, Q N, Sun, X N, Sun, Z B, Sun, P H T, Tam, Z B, Tang, W W, Tian, B D, Wang, C, Wang, H, Wang, H G, Wang, J C, Wang, J S, Wang, L P, Wang, L Y, Wang, R N, Wang, W, Wang, X G, Wang, X J, Wang, X Y, Wang, Y, Wang, Y D, Wang, Y J, Wang, Y P, Wang, Z H, Wang, Z X, Wang, Zhen, Wang, Zheng, Wang, D M, Wei, J J, Wei, Y J, Wei, T, Wen, C Y, Wu, H R, Wu, S, Wu, W X, Wu, X F, Wu, S Q, Xi, J, Xia, J J, Xia, G M, Xiang, D X, Xiao, G, Xiao, H B, Xiao, G G, Xin, Y L, Xin, Y, Xing, D L, Xu, R X, Xu, L, Xue, D H, Yan, J Z, Yan, C W, Yang, F F, Yang, J Y, Yang, L L, Yang, M J, Yang, R Z, Yang, S B, Yang, Y H, Yao, Z G, Yao, Y M, Ye, L Q, Yin, N, Yin, X H, You, Z Y, You, Y H, Yu, Q, Yuan, H D, Zeng, T X, Zeng, W, Zeng, Z K, Zeng, M, Zha, X X, Zhai, B B, Zhang, H M, Zhang, H Y, Zhang, J L, Zhang, J W, Zhang, L X, Zhang, Li, Zhang, Lu, Zhang, P F, Zhang, P P, Zhang, R, Zhang, S R, Zhang, S S, Zhang, X, Zhang, X P, Zhang, Y F, Zhang, Y L, Zhang, Yi, Zhang, Yong, Zhang, B, Zhao, J, Zhao, L, Zhao, L Z, Zhao, S P, Zhao, F, Zheng, Y, Zheng, B, Zhou, H, Zhou, J N, Zhou, P, Zhou, R, Zhou, X X, Zhou, C G, Zhu, F R, Zhu, H, Zhu, K J, Zhu, and X, Zuo

Subjects
General Physics and Astronomy
Abstract

Recently, the LHAASO Collaboration published the detection of 12 ultrahigh-energy γ-ray sources above 100 TeV, with the highest energy photon reaching 1.4 PeV. The first detection of PeV γ rays from astrophysical sources may provide a very sensitive probe of the effect of the Lorentz invariance violation (LIV), which results in decay of high-energy γ rays in the superluminal scenario and hence a sharp cutoff of the energy spectrum. Two highest energy sources are studied in this work. No signature of the existence of the LIV is found in their energy spectra, and the lower limits on the LIV energy scale are derived. Our results show that the first-order LIV energy scale should be higher than about 10^{5} times the Planck scale M_{Pl} and that the second-order LIV scale is10^{-3}M_{Pl}. Both limits improve by at least one order of magnitude the previous results.

Published
2021

11. Extended Very-High-Energy Gamma-Ray Emission Surrounding PSR J0622+3749 Observed by LHAASO-KM2A

Author

F, Aharonian, Q, An, Axikegu, L X, Bai, Y X, Bai, Y W, Bao, D, Bastieri, X J, Bi, Y J, Bi, H, Cai, J T, Cai, Z, Cao, J, Chang, J F, Chang, X C, Chang, B M, Chen, J, Chen, L, Chen, M J, Chen, M L, Chen, Q H, Chen, S H, Chen, S Z, Chen, T L, Chen, X L, Chen, Y, Chen, N, Cheng, Y D, Cheng, S W, Cui, X H, Cui, Y D, Cui, B Z, Dai, H L, Dai, Z G, Dai, Danzengluobu, D, Della Volpe, B, D'Ettorre Piazzoli, X J, Dong, J H, Fan, Y Z, Fan, Z X, Fan, J, Fang, K, Fang, C F, Feng, L, Feng, S H, Feng, Y L, Feng, B, Gao, C D, Gao, Q, Gao, W, Gao, M M, Ge, L S, Geng, G H, Gong, Q B, Gou, M H, Gu, J G, Guo, X L, Guo, Y Q, Guo, Y Y, Guo, Y A, Han, H H, He, H N, He, J C, He, S L, He, X B, He, Y, He, M, Heller, Y K, Hor, C, Hou, X, Hou, H B, Hu, S, Hu, S C, Hu, X J, Hu, D H, Huang, Q L, Huang, W H, Huang, X T, Huang, Z C, Huang, F, Ji, X L, Ji, H Y, Jia, K, Jiang, Z J, Jiang, C, Jin, D, Kuleshov, K, Levochkin, B B, Li, C, Li, F, Li, H B, Li, H C, Li, H Y, Li, J, Li, K, Li, W L, Li, X, Li, X R, Li, Y, Li, Y Z, Li, Z, Li, E W, Liang, Y F, Liang, S J, Lin, B, Liu, C, Liu, D, Liu, H, Liu, H D, Liu, J, Liu, J L, Liu, J S, Liu, J Y, Liu, M Y, Liu, R Y, Liu, S M, Liu, W, Liu, Y N, Liu, Z X, Liu, W J, Long, R, Lu, H K, Lv, B Q, Ma, L L, Ma, X H, Ma, J R, Mao, A, Masood, W, Mitthumsiri, T, Montaruli, Y C, Nan, B Y, Pang, P, Pattarakijwanich, Z Y, Pei, M Y, Qi, D, Ruffolo, V, Rulev, A, Sáiz, L, Shao, O, Shchegolev, X D, Sheng, J R, Shi, H C, Song, Yu V, Stenkin, V, Stepanov, Q N, Sun, X N, Sun, Z B, Sun, P H T, Tam, Z B, Tang, W W, Tian, B D, Wang, C, Wang, H, Wang, H G, Wang, J C, Wang, J S, Wang, L P, Wang, L Y, Wang, R N, Wang, W, Wang, X G, Wang, X J, Wang, X Y, Wang, Y D, Wang, Y J, Wang, Y P, Wang, Z, Wang, Z H, Wang, Z X, Wang, D M, Wei, J J, Wei, Y J, Wei, T, Wen, C Y, Wu, H R, Wu, S, Wu, W X, Wu, X F, Wu, S Q, Xi, J, Xia, J J, Xia, G M, Xiang, G, Xiao, H B, Xiao, G G, Xin, Y L, Xin, Y, Xing, D L, Xu, R X, Xu, L, Xue, D H, Yan, C W, Yang, F F, Yang, J Y, Yang, L L, Yang, M J, Yang, R Z, Yang, S B, Yang, Y H, Yao, Z G, Yao, Y M, Ye, L Q, Yin, N, Yin, X H, You, Z Y, You, Y H, Yu, Q, Yuan, H D, Zeng, T X, Zeng, W, Zeng, Z K, Zeng, M, Zha, X X, Zhai, B B, Zhang, H M, Zhang, H Y, Zhang, J L, Zhang, J W, Zhang, L, Zhang, L X, Zhang, P F, Zhang, P P, Zhang, R, Zhang, S R, Zhang, S S, Zhang, X, Zhang, X P, Zhang, Y, Zhang, Y F, Zhang, Y L, Zhang, B, Zhao, J, Zhao, L, Zhao, L Z, Zhao, S P, Zhao, F, Zheng, Y, Zheng, B, Zhou, H, Zhou, J N, Zhou, P, Zhou, R, Zhou, X X, Zhou, C G, Zhu, F R, Zhu, H, Zhu, K J, Zhu, X, Zuo, and X Y, Huang

Abstract

We report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (207.8 kyr) pulsar PSR J0622+3749 with the Large High-Altitude Air Shower Observatory (LHAASO). The source is detected with a significance of 8.2σ for E25 TeV assuming a Gaussian template. The best-fit location is (right ascension, declination) =(95.47°±0.11°,37.92°±0.09°), and the extension is 0.40°±0.07°. The energy spectrum can be described by a power-law spectrum with an index of -2.92±0.17_{stat}±0.02_{sys}. No clear extended multiwavelength counterpart of the LHAASO source has been found from the radio to sub-TeV bands. The LHAASO observations are consistent with the scenario that VHE electrons escaped from the pulsar, diffused in the interstellar medium, and scattered the interstellar radiation field. If interpreted as the pulsar halo scenario, the diffusion coefficient, inferred for electrons with median energies of ∼160 TeV, is consistent with those obtained from the extended halos around Geminga and Monogem and much smaller than that derived from cosmic ray secondaries. The LHAASO discovery of this source thus likely enriches the class of so-called pulsar halos and confirms that high-energy particles generally diffuse very slowly in the disturbed medium around pulsars.

Published
2021

12. Discovery of the Ultra-high energy gamma-ray source LHAASO J2108+5157

Author

Zhen Cao, F. Aharonian, Q. An, null Axikegu, L. X. Bai, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, H. Cai, J. T. Cai, Zhe Cao, J. Chang, J. F. Chang, B. M. Chen, E. S. Chen, J. Chen, Liang Chen, Long Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, X. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, S. W. Cui, X. H. Cui, Y. D. Cui, B. D’Ettorre Piazzoli, B. Z. Dai, H. L. Dai, Z. G. Dai, Dan-Zeng Dan-Zeng-Luo-Bu, D. della Volpe, X. J. Dong, K. K. Duan, J. H. Fan, Y. Z. Fan, Z. X. Fan, J. Fang, K. Fang, C. F. Feng, L. Feng, S. H. Feng, Y. L. Feng, B. Gao, C. D. Gao, L. Q. Gao, Q. Gao, W. Gao, M. M. Ge, L. S. Geng, G. H. Gong, Q. B. Gou, M. H. Gu, F. L. Guo, J. G. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, H. H. He, H. N. He, J. C. He, S. L. He, X. B. He, Y. He, M. Heller, Y. K. Hor, C. Hou, H. B. Hu, S. Hu, S. C. Hu, X. J. Hu, D. H. Huang, Q. L. Huang, W. H. Huang, X. T. Huang, X. Y. Huang, Z. C. Huang, F. Ji, X. L. Ji, H. Y. Jia, K. Jiang, Z. J. Jiang, C. Jin, T. Ke, D. Kuleshov, K. Levochkin, B. B. Li, Cheng Li, Cong Li, F. Li, H. B. Li, H. C. Li, H. Y. Li, J. Li, K. Li, W. L. Li, X. R. Li, Xin Li, Y. Li, Y. Z. Li, Zhe Li, Zhuo Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, J. S. Liu, J. Y. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. Liu, Y. N. Liu, Z. X. Liu, W. J. Long, R. Lu, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, A. Masood, Z. Min, W. Mitthumsiri, T. Montaruli, Y. C. Nan, B. Y. Pang, P. Pattarakijwanich, Z. Y. Pei, M. Y. Qi, Y. Q. Qi, B. Q. Qiao, J. J. Qin, D. Ruffolo, V. Rulev, A. Sáiz, L. Shao, O. Shchegolev, X. D. Sheng, J. Y. Shi, H. C. Song, Yu. V. Stenkin, V. Stepanov, Y. Su, Q. N. Sun, X. N. Sun, Z. B. Sun, P. H. T. Tam, Z. B. Tang, W. W. Tian, B. D. Wang, C. Wang, H. Wang, H. G. Wang, J. C. Wang, J. S. Wang, L. P. Wang, L. Y. Wang, R. N. Wang, W. Wang, X. G. Wang, X. J. Wang, X. Y. Wang, Y. Wang, Y. D. Wang, Y. J. Wang, Y. P. Wang, Z. H. Wang, Z. X. Wang, Zhen Wang, Zheng Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, S. Wu, W. X. Wu, X. F. Wu, S. Q. Xi, J. Xia, J. J. Xia, G. M. Xiang, D. X. Xiao, G. Xiao, H. B. Xiao, G. G. Xin, Y. L. Xin, Y. Xing, D. L. Xu, R. X. Xu, L. Xue, D. H. Yan, J. Z. Yan, C. W. Yang, F. F. Yang, J. Y. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, S. B. Yang, Y. H. Yao, Z. G. Yao, Y. M. Ye, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. D. Zeng, T. X. Zeng, W. Zeng, Z. K. Zeng, M. Zha, X. X. Zhai, B. B. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, J. W. Zhang, L. X. Zhang, Li Zhang, Lu Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. F. Zhang, Y. L. Zhang, Yi Zhang, Yong Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, F. Zheng, Y. Zheng, B. Zhou, H. Zhou, J. N. Zhou, P. Zhou, R. Zhou, X. X. Zhou, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, and X. Zuo

Subjects
Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Molecular cloud, Astrophysics::High Energy Astrophysical Phenomena, Hadron, Gamma ray, Flux, Sigma, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Gamma-ray astronomy, Space and Planetary Science, Energy spectrum, Ultrahigh energy, Astrophysics - High Energy Astrophysical Phenomena
Abstract

We report the discovery of a UHE gamma-ray source, LHAASO J2108+5157, by analyzing the LHAASO-KM2A data of 308.33 live days. Significant excess of gamma-ray induced showers is observed in both energy bands of 25-100 TeV and $\gt$100 TeV with 9.5 sigma and 8.5 sigma, respectively. This source is not significantly favored as an extensive source with the angular extension smaller than the point-spread function of KM2A. The measured energy spectrum from 20 to 200 TeV can be approximately described by a power-law function with an index of -2.83$\pm$ 0.18stat. A harder spectrum is demanded at lower energies considering the flux upper limit set by Fermi-LAT observations. The position of the gamma-ray emission is correlated with a giant molecular cloud, which favors a hadronic origin. No obvious counterparts have been found, deeper multiwavelength observations will help to shed new light on this intriguing UHE source., Comment: 12 pages, 7 figures, accepted by ApJL

Published
2021
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13. Prospects for a Multi-TeV Gamma-ray Sky Survey with the LHAASO Water Cherenkov Detector Array

Author

Guoqing Xiao, Bo Gao, Yu-Hua Yao, B. Q. Qiao, E. W. Liang, X. G. Wang, Yong Zhang, X. C. Chang, X. H. Cui, S. Wu, F. Y. Li, M. M. Ge, H. L. Dai, L. X. Bai, Z. G. Yao, Lei Zhao, Chang Jin, L. Chen, J. W. Zhao, H. D. Liu, Duo Yan, BZ Zhao, Z. X. Liu, Y. C. Nan, H. B. Li, H. K. Lv, B. D'Ettorre Piazzoli, W. X. Wu, Xiao-Yang Zhang, Y. D. Cheng, Z. H. Wang, F. R. Zhu, Y. Wang, M. Zha, P. Zhou, Yi Chen, C. X. Liu, Xufang Li, Yinong Liu, Jun-Jie Wei, Y. Y. Guo, R. Y. Liu, X. F. Wu, L. Zhang, X. J. Wang, H. M. Zhang, V. Rulev, Xiao-Hu Zhang, Y. Yu, C. Y. Wu, Zhe Cao, W. H. Huang, Guanghua Gong, Li-Sheng Geng, B. M. Chen, L. Xue, B. Liu, L. L. Yang, D. H. Huang, Y. A. Han, B. B. Zhang, D. M. Wei, Y. D. Cui, S. R. Zhang, Ziyi Wang, Zhengguo Cao, X. L. Ji, R. Lu, Jianrong Zhou, M. J. Yang, Z. Y. Pei, Y. M. Ye, S. P. Chao, H. C. Li, Jun He, Qiang Yuan, G. M. Xiang, Z. J. Jiang, Jiaxing Li, V. Alekseenko, J. F. Chang, Danzengluobu, H. Y. Jia, J. Chen, Zebo Tang, P. Pattarakijwanich, J. S. Liu, H. Y. Zhang, J. R. Mao, Wang Yanfang, H. Wang, D. Bastieri, Liang-Liang Wang, Jie Zhang, Teresa Montaruli, Cong Li, Y. Li, K. Levochkin, X. J. Bi, T. X. Zeng, Chao-Peng Wang, J. W. Zhang, S. Z. Chen, H. Liu, X. D. Sheng, Yu. V. Stenkin, C. Hou, H. Zhu, Z. K. Zeng, P. P. Zhang, P. F. Zhang, Wenwu Tian, W. J. Long, Lanqing Ma, G. G. Xin, S. H. Feng, X. Y. Wang, X. Zuo, J. C. Wang, W. H. Wang, R. Zhou, N. Yin, H. B. Hu, C. F. Feng, S. M. Liu, X. T. Huang, Yi Zhang, N. Cheng, Cheng Li, Ying Zhang, Hong-Jie Li, H. Li, Y. Zheng, M. L. Chen, Axikegu, S. B. Yang, S. W. Cui, F. Ji, J. H. Fan, Y. Z. Fan, Bo-Qiang Ma, C. W. Yang, L. Feng, Z. G. Dai, L. Z. Zhao, L. Q. Yin, Wang Yingjie, Wei Liu, Zujian Wang, Z. Li, W. Zeng, Shengxue Zhang, Q. B. Gou, Huihai He, M. H. Gu, J. Fang, X. L. Chen, H. G. Wang, O. Shchegolev, S. L. He, K. Jiang, F. Zheng, T. L. Chen, W. Gao, T. Wen, L. Shao, Yucheng Feng, M. Y. Qi, X. X. Zhou, Yiwei Wang, Felix Aharonian, K. Li, Y. F. Liang, Ruizhi Yang, Y. W. Bao, David Ruffolo, Z. Y. You, S. Hu, J. Y. Liu, Ming Chen, Warit Mitthumsiri, V. Stepanov, Q. An, Q. Gao, K. J. Zhu, Z. B. Sun, P. H. T. Tam, Y. Q. Guo, H. R. Wu, B. Z. Dai, D. Liu, M. Heller, Sina Chen, H. D. Zeng, X. H. You, Renxin Xu, C. G. Zhu, Minghui Liu, X. H. Ma, Y. He, J. R. Shi, Yuan-Ming Xing, F. F. Yang, X. X. Li, W. L. Li, Q. H. Chen, D. della Volpe, Huang Qiyan, A. Masood, H. Cai, and Alejandro Sáiz

Subjects
Nuclear and High Energy Physics, Active galactic nucleus, Cherenkov detector, media_common.quotation_subject, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, High Energy Physics - Experiment, law.invention, Hochenergie-Astrophysik Theorie - Abteilung Hinton, High Energy Physics - Experiment (hep-ex), Observatory, law, 0103 physical sciences, 010306 general physics, Instrumentation, media_common, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), 010308 nuclear & particles physics, Astrophysics::Instrumentation and Methods for Astrophysics, Order (ring theory), Astronomy and Astrophysics, Projection (relational algebra), Air shower, Sky, High Energy Physics::Experiment, Astrophysics - High Energy Astrophysical Phenomena, Energy (signal processing)
Abstract

The Water Cherenkov Detector Array (WCDA) is a major component of the Large High Altitude Air Shower Array Observatory (LHAASO), a new generation cosmic-ray experiment with unprecedented sensitivity, currently under construction. The WCDA is aimed at the study of TeV $\gamma$-rays. In order to evaluate the prospects of searching for TeV $\gamma$-ray sources with the WCDA, we present in this paper a projection for the one-year sensitivity of the WCDA to TeV $\gamma$-ray sources from TeVCat (footnote: http://tevcat.uchicago.edu) using an all-sky approach. Out of 128 TeVCat sources observable to the WCDA up to a zenith angle of $45^\circ$, we estimate that 42 would be detectable for one year of observations at a median energy of 1 TeV. Most of them are Galactic sources, and the extragalactic sources are Active Galactic Nuclei (AGN)., Comment: 10 pages,10 figures, it is to be published in Chinese Physics C

Published
2020
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14. Absolute calibration of LHAASO WFCTA camera based on LED

Author

W. J. Long, Rong Xu, Cong Li, J. J. Xia, Houdun Zeng, Axikegu, Yongchun Wang, H. H. He, Xufang Li, X. X. Zhai, Y. D. Cui, L. Feng, H. B. Li, F. R. Zhu, Qie Sun, Yi Chen, F. Y. Li, C. F. Feng, D. H. Huang, Bin Zhou, J. Y. Shi, V. I. Stepanov, H. Zhu, Jun-Jie Wei, L. Z. Zhao, F. Ji, M. Zha, Jia Zhang, Y. H. Yao, Yi Zhang, B. Q. Qiao, Rui Zhang, Linbin Yang, Zhengguo Cao, M. L. Chen, Jianeng Zhou, Jian Wang, Chiming Jin, Zhe Cao, M. M. Ge, X. Zuo, Xuliang Chen, D.A. Kuleshov, Hong-Guang Wang, Y. He, Xiang-Yu Wang, E. S. Chen, Y. A. Han, N. Cheng, J. Fang, S. Hu, J. Y. Liu, G. M. Xiang, H. C. Song, S. P. Zhao, Zebo Tang, H. B. Xiao, W. Liu, L. X. Bai, Binyu Zhao, Yun-Feng Liang, Tao Zeng, Jixia Li, W. Zeng, Bin Ma, Donglian Xu, Z. Min, Xuelong Wang, Xiaofei Zhang, X. L. Guo, X. J. Dong, Hefan Li, S. H. Feng, Q. H. Chen, G. G. Xin, Warit Mitthumsiri, Kai-Kai Duan, Ying Zhang, P. F. Zhang, Z. X. Wang, H.Y. Gan, T. Wen, S. W. Cui, K. Levochkin, Hao Zhou, W. Wang, P. Pattarakijwanich, Kun Fang, D. M. Wei, H. Cai, S. Wu, Sina Chen, X. D. Sheng, Minghao Qi, C. X. Liu, Y. L. Feng, D. Bastieri, Q. An, B. Y. Pang, B. Liu, B. D. Wang, T. Ke, S. B. Yang, Bai Yibing, Lidan Gao, Y. W. Bao, Y. C. Nan, S. Z. Chen, Zhe Li, Shi-Qi Hu, X. H. You, H. B. Hu, H. Liu, X. T. Huang, J. C. He, Bingshui Gao, R. Zhou, L. Y. Wang, Z. H. Wang, Li Zhang, Z. G. Dai, M. J. Yang, Fan Yang, A. Masood, David Ruffolo, C. W. Yang, Q. Gao, Jun Liu, Z. K. Zeng, C. D. Gao, Lei Zhao, Z. C. Huang, B. B. Li, G. H. Gong, Lang Shao, M. J. Chen, Y. J. Wang, H. M. Zhang, D. della Volpe, He Zhang, Jianguo Qin, Y. J. Bi, Jun-Hui Fan, H. D. Liu, W. H. Huang, Y. D. Cheng, Z. B. Sun, Bo Zhang, Duo Yan, Z. X. Liu, Ruizhi Yang, X. N. Sun, Li-Sheng Geng, S. L. He, W. L. Li, Y. P. Wang, Y. H. Yu, Z. G. Yao, D. X. Xiao, J.W. Xia, X. G. Wang, H. L. Dai, Y. Y. Guo, Danzengluobu, Y. Q. Qi, H. Wang, W. Gao, Yi Liu, J. B. Zhao, Y. K. Hor, J. Chen, Zheng Wang, Q. B. Gou, L. P. Wang, Qizhi Huang, T. L. Chen, X. F. Wu, X. L. Ji, R. Lu, Cheng Guang Zhu, Zhuo Li, T. Montaruli, S. Q. Xi, Zhen Wang, Y.T. Fu, G. C. Xiao, Y. Z. Fan, X. H. Cui, Z. Y. Pei, B. D'Ettorre Piazzoli, W. X. Wu, H. Y. Jia, Y. Wang, B. Z. Dai, Alejandro Sáiz, Youping Li, J. T. Cai, R. Liu, Long Chen, Y. J. Wei, Fengqin Guo, J. F. Chang, V. Rulev, L. Xue, Liang Chen, Y. L. Xin, Yugang Zhang, Xinbo He, K. Jiang, X. J. Bi, X. J. Hu, Y. Zheng, L. Q. Yin, X. Y. Huang, J. W. Zhang, P. P. Zhang, Wenwu Tian, Pak-Hin Thomas Tam, H. C. Li, Z. X. Fan, Z. Y. You, J. Y. Yang, Ping Zhou, Junjie Mao, Y. Z. Li, F. Zheng, Y. Q. Guo, H. R. Wu, B. M. Chen, X. X. Zhou, Q. Yuan, Felix Aharonian, H. N. He, M. Heller, K. Li, L. L. Ma, Yu. V. Stenkin, Z. J. Jiang, J. Liu, Yong Zhang, R. N. Wang, C. Hou, Shuibin Lin, S. M. Liu, Lu Zhang, J. S. Wang, Cunguo Wang, E. W. Liang, N. Yin, K. J. Zhu, Minghui Liu, Shengxue Zhang, Cheng Li, Dong Liu, Jinyao Liu, C. Y. Wu, Y. M. Ye, Yunchao Liu, Y. M. Xing, H. K. Lv, X. H. Ma, Xiang Zhang, Y. Su, J. G. Guo, S. R. Zhang, M. H. Gu, L. X. Zhang, Jiawei Yan, Xin Li, and Oleg Shchegolev

Subjects
Physics, Nuclear and High Energy Physics, Photon, business.industry, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Cosmic ray, Metrology, law.invention, Telescope, Air shower, Silicon photomultiplier, Optics, law, Calibration, business, Instrumentation, Cherenkov radiation
Abstract

The main scientific goal of the LHAASO WFCTA experiment is to measure the cosmic ray energy spectra and composition from 10 TeV to 1 EeV. Cherenkov photons in the extensive air shower measured by the SiPM camera of Cherenkov telescopes can be used to reconstruct the cosmic ray energy. The absolute calibration of the camera is a crucial step to achieve the accurate measurement of the cosmic ray energy spectrum. A multi-wavelength cylindrical illuminator based on LEDs is developed and mounted inside the telescope to calibrate and monitor the camera, and the illuminator’s stability is better than 0.5% under the temperature variation from -26 to 26 ° C. A portable probe with a single photoelectron resolution of 21.6% is developed. After calibration by National Institute of Metrology, China (NIM), the probe is taken to the LHAASO site to measure the absolute photon density of the cylindrical illuminator inside the telescope. Based on the illuminator with known photon density, the photon conversion factor of the camera can be calibrated, and the overall calibration uncertainty is less than 2.6%.

Published
2022

15. Geometrical reconstruction of fluorescence events observed by the LHAASO experiment *

Author

F. Aharonian, Q. An, null Axikegu, L. X. Bai, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, H. Cai, J. T. Cai, Z. Cao, J. Chang, J. F. Chang, X. C. Chang, B. M. Chen, J. Chen, L. Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, X. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, null Danzengluobu, D. della Volpe, B. D'Ettorre Piazzoli, X. J. Dong, J. H. Fan, Y. Z. Fan, Z. X. Fan, J. Fang, K. Fang, C. F. Feng, L. Feng, S. H. Feng, Y. L. Feng, B. Gao, C. D. Gao, Q. Gao, W. Gao, M. M. Ge, L. S. Geng, G. H. Gong, Q. B. Gou, M. H. Gu, J. G. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, H. H. He, H. N. He, J. C. He, S. L. He, X. B. He, Y. He, M. Heller, Y. K. Hor, C. Hou, X. Hou, H. B. Hu, S. Hu, S. C. Hu, X. J. Hu, D. H. Huang, Q. L. Huang, W. H. Huang, X. T. Huang, Z. C. Huang, F. Ji, X. L. Ji, H. Y. Jia, K. Jiang, Z. J. Jiang, C. Jin, D. Kuleshov, K. Levochkin, B. B. Li, C. Li, F. Li, H. B. Li, H. C. Li, H. Y. Li, J. Li, K. Li, W. L. Li, X. Li, X. R. Li, Y. Li, Y. Z. Li, Z. Li, E. W. Liang, Y. F. Liang, S.J. Lin, B. Liu, C. Liu, D. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, J. S. Liu, J. Y. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. N. Liu, Z. X. Liu, W. J. Long, R. Lu, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, A. Masood, W. Mitthumsiri, T. Montaruli, Y. C. Nan, B. Y. Pang, P. Pattarakijwanich, Z. Y. Pei, M. Y. Qi, D. Ruffolo, V. Rulev, A. Sáiz, L. Shao, O. Shchegolev, X. D. Sheng, J. R. Shi, H. C. Song, Yu.V. Stenkin, V. Stepanov, Q. N. Sun, X. N. Sun, Z. B. Sun, P. H. T. Tam, Z. B. Tang, W. W. Tian, B. D. Wang, C. Wang, H. Wang, H. G. Wang, J. C. Wang, J. S. Wang, L. P. Wang, L. Y. Wang, R. N. Wang, W. Wang, X. G. Wang, X. J. Wang, X. Y. Wang, Y. D. Wang, Y. J. Wang, Y. P. Wang, Z. Wang, Z. H. Wang, Z. X. Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, S. Wu, W. X. Wu, X. F. Wu, S. Q. Xi, J. Xia, J. J. Xia, G. M. Xiang, G. Xiao, H. B. Xiao, G. G. Xin, Y. L. Xin, Y. Xing, D. L. Xu, R. X. Xu, L. Xue, D. H. Yan, C. W. Yang, F. F. Yang, J. Y. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, S. B. Yang, Y. H. Yao, Z. G. Yao, Y. M. Ye, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. D. Zeng, T. X. Zeng, W. Zeng, Z. K. Zeng, M. Zha, X. X. Zhai, B. B. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, J. W. Zhang, L. Zhang, L. X. Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. Zhang, Y. F. Zhang, Y. L. Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, F. Zheng, Y. Zheng, B. Zhou, H. Zhou, J. N. Zhou, P. Zhou, R. Zhou, X. X. Zhou, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, and X. Zuo

Subjects
Physics, Nuclear and High Energy Physics, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, business.industry, Astrophysics::High Energy Astrophysical Phenomena, Detector, Resolution (electron density), Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Cosmic ray, 01 natural sciences, Fluorescence, law.invention, Telescope, Optics, law, 0103 physical sciences, Trajectory, Range (statistics), 010306 general physics, business, Instrumentation, Cherenkov radiation
Abstract

The LHAASO-WFCTA experiment, which aims to observe cosmic rays in the sub-EeV range using the fluorescence technique, uses a new generation of high-performance telescopes. To ensure that the experiment has excellent detection capability associated with the measurement of the energy spectrum, the primary composition of cosmic rays, and so on, an accurate geometrical reconstruction of air-shower events is fundamental. This paper describes the development and testing of geometrical reconstruction for stereo viewed events using the WFCTA (Wide Field of view Cherenkov/Fluorescence Telescope Array) detectors. Two approaches, which take full advantage of the WFCTA detectors, are investigated. One is the stereo-angular method, which uses the pointing of triggered SiPMs in the shower trajectory, and the other is the stereo-timing method, which uses the triggering time of the fired SiPMs. The results show that both methods have good geometrical resolution; the resolution of the stereo-timing method is slightly better than the stereo-angular method because the resolution of the latter is slightly limited by the shower track length.

Published
2021

16. Influence of the Access of Distributed Generation on the Distribution Network System of Inner Mongolia Power Grid and Countermeasure Analysis

Author

X L Yi, Y Q Li, Sarengaowa, H Yuan, Z B Sun, K Tao, and H L Fan

Subjects
Countermeasure, Distribution networks, Computer science, business.industry, Distributed computing, Distributed generation, Power grid, Inner mongolia, business
Abstract

Solar energy resource is highly rich in Inner Mongolia regions, and the customers utilized electric are scattered in the vast grassland. Thus, the distributed generation with its unique performance and high quality, has been developed rapidly in recent years. However, the large-scale distributed power supply has brought many unpredictable impacts when they are accessed to the distribution network, even seriously affecting the safe and stable operation of the distribution network. In this work, the technical barriers caused by distributed power generation to the grid-connected have been explored. In addition, the constraints and key influencing factors of distributed generation on distribution network have also been analysed and a safe and stable operation strategy to access distributed photovoltaic power supply into the network has proposed. The results here could provide a theoretical guidance for the rapid formulation and optimization of the distributed power accessing into grid network in Inner Mongolia power grid.

Published
2021

17. Observation of the Crab Nebula with LHAASO-KM2A − a performance study *

Author

F. Aharonian, Q. An, 克古 Axikegu, L. X. Bai, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, H. Cai, J. T. Cai, Z. Cao, J. Chang, J. F. Chang, X. C. Chang, B. M. Chen, J. Chen, L. Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, X. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, 罗布 Danzengluobu, D. della Volpe, B. D'Ettorre Piazzoli, X. J. Dong, J. H. Fan, Y. Z. Fan, Z. X. Fan, J. Fang, K. Fang, C. F. Feng, L. Feng, S. H. Feng, Y. L. Feng, B. Gao, C. D. Gao, Q. Gao, W. Gao, M. M. Ge, L. S. Geng, G. H. Gong, Q. B. Gou, M. H. Gu, J. G. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, H. H. He, H. N. He, J. C. He, S. L. He, X. B. He, Y. He, M. Heller, Y. K. Hor, C. Hou, X. Hou, H. B. Hu, S. Hu, S. C. Hu, X. J. Hu, D. H. Huang, Q. L. Huang, W. H. Huang, X. T. Huang, Z. C. Huang, F. Ji, X. L. Ji, H. Y. Jia, K. Jiang, Z. J. Jiang, C. Jin, D. Kuleshov, K. Levochkin, B. B. Li, C. Li, F. Li, H. B. Li, H. C. Li, H. Y. Li, J. Li, K. Li, W. L. Li, X. Li, X. R. Li, Y. Li, Y. Z. Li, Z. Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, J. S. Liu, J. Y. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. N. Liu, Z. X. Liu, W. J. Long, R. Lu, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, A. Masood, W. Mitthumsiri, T. Montaruli, Y. C. Nan, B. Y. Pang, P. Pattarakijwanich, Z. Y. Pei, M. Y. Qi, D. Ruffolo, V. Rulev, A. Sáiz, L. Shao, O. Shchegolev, X. D. Sheng, J. R. Shi, H. C. Song, Yu. V. Stenkin, V. Stepanov, Q. N. Sun, X. N. Sun, Z. B. Sun, P. H. T. Tam, Z. B. Tang, W. W. Tian, B. D. Wang, C. Wang, H. Wang, H. G. Wang, J. C. Wang, J. S. Wang, L. P. Wang, L. Y. Wang, R. N. Wang, W. Wang, X. G. Wang, X. J. Wang, X. Y. Wang, Y. D. Wang, Y. J. Wang, Y. P. Wang, Z. Wang, Z. H. Wang, Z. X. Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, S. Wu, W. X. Wu, X. F. Wu, S. Q. Xi, J. Xia, J. J. Xia, G. M. Xiang, G. Xiao, H. B. Xiao, G. G. Xin, Y. L. Xin, Y. Xing, D. L. Xu, R. X. Xu, L. Xue, D. H. Yan, C. W. Yang, F. F. Yang, J. Y. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, S. B. Yang, Y. H. Yao, Z. G. Yao, Y. M. Ye, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. D. Zeng, T. X. Zeng, W. Zeng, Z. K. Zeng, M. Zha, X. X. Zhai, B. B. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, J. W. Zhang, L. Zhang, L. X. Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. Zhang, Y. F. Zhang, Y. L. Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, F. Zheng, Y. Zheng, B. Zhou, H. Zhou, J. N. Zhou, P. Zhou, R. Zhou, X. X. Zhou, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, and X. Zuo

Subjects
Physics, Nuclear and High Energy Physics, High energy, 010308 nuclear & particles physics, Cosmic distance ladder, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Crab Nebula, 0103 physical sciences, Energy spectrum, 010306 general physics, Instrumentation, Energy (signal processing)
Abstract

A sub-array of the Large High Altitude Air Shower Observatory (LHAASO), KM2A is mainly designed to observe a large fraction of the northern sky to hunt for γ-ray sources at energies above 10 TeV. Even though the detector construction is still underway, half of the KM2A array has been operating stably since the end of 2019. In this paper, we present the KM2A data analysis pipeline and the first observation of the Crab Nebula, a standard candle in very high energy γ-ray astronomy. We detect γ-ray signals from the Crab Nebula in both energy ranges of 10 100 TeV and 100 TeV with high significance, by analyzing the KM2A data of 136 live days between December 2019 and May 2020. With the observations, we test the detector performance, including angular resolution, pointing accuracy and cosmic-ray background rejection power. The energy spectrum of the Crab Nebula in the energy range 10-250 TeV fits well with a single power-law function dN/dE = (1.13 0.05 0.08 ) 10 (E/20 TeV) cm s TeV . It is consistent with previous measurements by other experiments. This opens a new window of γ-ray astronomy above 0.1 PeV through which new ultrahigh-energy γ-ray phenomena, such as cosmic PeVatrons, might be discovered.

Published
2021

18. The design and preliminary test of a stripline kicker for HALS

Author

F. L. Shang, W. B. Song, L. Shang, W. Liu, and Z. B. Sun

Subjects
History, Materials science, Acoustics, High voltage, Electrical impedance, Stripline, Computer Science Applications, Education, Test (assessment)
Abstract

Stripline kicker is an important component of both on-axis longitudinal accumulation [1] and on-axis swap out injection schemes in HALS (Hefei Advanced Light Source). After more than one year of R&D, construction of the first prototype is completed. The kicker performance is simulated. The results show that in the range of 0 ~ 1 GHz, on differential mode, S11 is less than - 20 dB. In order to facilitate installation, the extension part and PTEF bracket were designed. The assembly of kicker and commercial feedthrough has been tested with pulse generator and network analyzer.

Published
2019

19. A note on the B*B̄, B*B̄*, D*D̄, D*D̄* molecular states

Author

Xiang Liu, Shi-Lin Zhu, Zhi-Gang Luo, Jun He, and Z. B. Sun

Subjects
Physics, Nuclear and High Energy Physics, Theoretical physics, Astronomy and Astrophysics, Quantum number, Instrumentation, Mixing (physics), Experimental research
Abstract

In the framework of the one-boson-exchange model, we have performed an extensive study of the possible B*, B**, D*, D** molecular states with various quantum numbers after considering the S-wave and D-wave mixing. We also discuss the possible experimental research of these interesting states.

Published
2012

20. Topocaustics

Author

L.-Y. Oey, Y.-L. Chang, Z.-B. Sun, and X.-H. Lin

Subjects
Atmospheric Science, Computer Science (miscellaneous), Geotechnical Engineering and Engineering Geology, Oceanography
Published
2009

21. Microstructure and characteristics of rapid sintered low friction, wear resistant 80Ni20Cr–Cr2O3–Ag–BaF2/CaF2coating

Author

Z. B. Sun, C. H. Ding, Zhimao Yang, and S. M. Cui

Subjects
Materials science, Mechanical Engineering, Metallurgy, Sintering, engineering.material, Condensed Matter Physics, Microstructure, Indentation hardness, Superalloy, Coating, Mechanics of Materials, engineering, Relative density, General Materials Science, Lubricant, Eutectic system
Abstract

A PM304 composite coating comprising a 80Ni20Cr matrix (60 wt-%) containing Cr2O3 (20%), Ag (10%) and eutectic BaF2/CaF2 (10%) as wear resistant or solid lubricant additives, designed for operation up to 650°C, has been successfully prepared by cold isostatic pressing milled powder onto a Ni based superalloy rod and rapid induction sintering. The size of Cr2O3 and BaF2/CaF2 particles was

Published
2008

22. Evidence for e+e− →γχc1,2 at center-of-mass energies from 4.009 to 4.360 GeVSupported by National Key Basic Research Program of China (2015CB856700), Joint Funds of National Natural Science Foundation of China (11079008, 11179007, U1232201, U1332201, U1232107), National Natural Science Foundation of China (NSFC) (10935007, 11121092, 11125525, 11235011, 11322544, 11335008), Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program, CAS (KJCX2-YW-N29, KJCX2-YW-N45), 100 Talents Program of CAS, INPAC and Shanghai Key Laboratory for Particle Physics and Cosmology; German Research Foundation DFG (Collaborative Research Center CRC-1044), Istituto Nazionale di Fisica Nucleare, Italy, Ministry of Development of Turkey (DPT2006K-120470), Russian Foundation for Basic Research (14-07-91152), U. S. Department of Energy (DE-FG02-04ER41291, DE-FG02-05ER41374, DE-FG02-94ER40823, DESC0010118), U.S. National Science Foundation, University of Groningen (RuG) and Helmholtzzentrum fuer Schwerionenforschung GmbH (GSI), Darmstadt, WCU Program of National Research Foundation of Korea (R32-2008-000-10155-0)

Author

Ablikim, M.Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China, Achasov, M. N.(G.I. Budker Institute of Nuclear Physics SB RAS (BINP), Novosibirsk 630090, Russia), Ai, X. C.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Albayrak, O.(Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA), Albrecht, M.(Bochum Ruhr-University, D-44780 Bochum, Germany), Ambrose, D. J.(University of Rochester, Rochester, New York 14627, USA), Amoroso, A.(University of Turin, I-10125, Turin, Italy), An, F. F.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), An, Q.(University of Science and Technology of China, Hefei 230026, China), Bai, J. Z.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Ferroli, R. Baldini(INFN Laboratori Nazionali di Frascati, I-00044, Frascati, Italy), Ban, Y.(Peking University, Beijing 100871, China), Bennett, D. W.(Indiana University, Bloomington, Indiana 47405, USA), Bennett, J. V.(Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA), Bertani, M.(INFN Laboratori Nazionali di Frascati, I-00044, Frascati, Italy), Bettoni, D.(INFN Sezione di Ferrara, I-44122, Ferrara, Italy), Bian, J. M.(University of Minnesota, Minneapolis, Minnesota 55455, USA), Bianchi, F.(University of Turin, I-10125, Turin, Italy), Boger, E.(Joint Institute for Nuclear Research, 141980 Dubna, Moscow region, Russia), Bondarenko, O.(KVI-CART, University of Groningen, NL-9747 AA Groningen, The Netherlands), Boyko, I.(Joint Institute for Nuclear Research, 141980 Dubna, Moscow region, Russia), Briere, R. A.(Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA), Cai, H.(Wuhan University, Wuhan 430072, China), Cai, X.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Cakir, O.(Istanbul Aydin University, 34295 Sefakoy, Istanbul, Turkey), Calcaterra, A.(INFN Laboratori Nazionali di Frascati, I-00044, Frascati, Italy), Cao, G. F.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Cetin, S. A.(Dogus University, 34722 Istanbul, Turkey), Chang, J. F.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Chelkov, G.(Joint Institute for Nuclear Research, 141980 Dubna, Moscow region, Russia), Chen, G.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Chen, H. S.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Chen, H. Y.(Beihang University, Beijing 100191, China), Chen, J. C.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Chen, M. L.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Chen, S. J.(Nanjing University, Nanjing 210093, China), Chen, X.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Chen, X. R.(Lanzhou University, Lanzhou 730000, China), Chen, Y. B.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Cheng, H. P.(Huangshan College, Huangshan 245000, China), Chu, X. K.(Peking University, Beijing 100871, China), Cibinetto, G.(INFN Sezione di Ferrara, I-44122, Ferrara, Italy), Cronin-Hennessy, D.(University of Minnesota, Minneapolis, Minnesota 55455, USA), Dai, H. L.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Dai, J. P.(Shanghai Jiao Tong University, Shanghai 200240, China), Dbeyssi, A.(Helmholtz Institute Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany), Dedovich, D.(Joint Institute for Nuclear Research, 141980 Dubna, Moscow region, Russia), Deng, Z. Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Denig, A.(Johannes Gutenberg University of Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany), Denysenko, I.(Joint Institute for Nuclear Research, 141980 Dubna, Moscow region, Russia), Destefanis, M.(University of Turin, I-10125, Turin, Italy), Mori, F. De(University of Turin, I-10125, Turin, Italy), Ding, Y.(Liaoning University, Shenyang 110036, China), Dong, C.(Nankai University, Tianjin 300071, China), Dong, J.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Dong, L. Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Dong, M. Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Du, S. X.(Zhengzhou University, Zhengzhou 450001, China), Duan, P. F.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Fan, J. Z.(Tsinghua University, Beijing 100084, China), Fang, J.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Fang, S. S.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Fang, X.(University of Science and Technology of China, Hefei 230026, China), Fang, Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Fava, L.(University of Eastern Piedmont, I-15121, Alessandria, Italy), Feldbauer, F.(Johannes Gutenberg University of Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany), Felici, G.(INFN Laboratori Nazionali di Frascati, I-00044, Frascati, Italy), Feng, C. Q.(University of Science and Technology of China, Hefei 230026, China), Fioravanti, E.(INFN Sezione di Ferrara, I-44122, Ferrara, Italy), Fritsch, M.(Helmholtz Institute Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany), Fu, C. D.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Gao, Q.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Gao, Y.(Tsinghua University, Beijing 100084, China), Gao, Z.(University of Science and Technology of China, Hefei 230026, China), Garzia, I.(INFN Sezione di Ferrara, I-44122, Ferrara, Italy), Goetzen, K.(GSI Helmholtzcentre for Heavy Ion Research GmbH, D-64291 Darmstadt, Germany), Gong, W. X.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Gradl, W.(Johannes Gutenberg University of Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany), Greco, M.(University of Turin, I-10125, Turin, Italy), Gu, M. H.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Gu, Y. T.(Guangxi University, Nanning 530004, China), Guan, Y. H.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Guo, A. Q.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Guo, L. B.(Nanjing Normal University, Nanjing 210023, China), Guo, T.(Nanjing Normal University, Nanjing 210023, China), Guo, Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Guo, Y. P.(Johannes Gutenberg University of Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany), Haddadi, Z.(KVI-CART, University of Groningen, NL-9747 AA Groningen, The Netherlands), Hafner, A.(Johannes Gutenberg University of Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany), Han, S.(Wuhan University, Wuhan 430072, China), Han, Y. L.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Harris, F. A.(University of Hawaii, Honolulu, Hawaii 96822, USA), He, K. L.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), He, Z. Y.(Nankai University, Tianjin 300071, China), Held, T.(Bochum Ruhr-University, D-44780 Bochum, Germany), Heng, Y. K.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Hou, Z. L.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Hu, C.(Nanjing Normal University, Nanjing 210023, China), Hu, H. M.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Hu, J. F.(University of Turin, I-10125, Turin, Italy), Hu, T.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Hu, Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Huang, G. M.(Central China Normal University, Wuhan 430079, China), Huang, G. S.(University of Science and Technology of China, Hefei 230026, China), Huang, H. P.(Wuhan University, Wuhan 430072, China), Huang, J. S.(Henan Normal University, Xinxiang 453007, China), Huang, X. T.(Shandong University, Jinan 250100, China), Huang, Y.(Nanjing University, Nanjing 210093, China), Hussain, T.(University of the Punjab, Lahore-54590, Pakistan), Ji, Q.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Ji, Q. P.(Nankai University, Tianjin 300071, China), Ji, X. B.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Ji, X. L.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Jiang, L. L.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Jiang, L. W.(Wuhan University, Wuhan 430072, China), Jiang, X. S.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Jiao, J. B.(Shandong University, Jinan 250100, China), Jiao, Z.(Huangshan College, Huangshan 245000, China), Jin, D. P.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Jin, S.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Johansson, T.(Uppsala University, Box 516, SE-75120 Uppsala, Sweden), Julin, A.(University of Minnesota, Minneapolis, Minnesota 55455, USA), Kalantar-Nayestanaki, N.(KVI-CART, University of Groningen, NL-9747 AA Groningen, The Netherlands), Kang, X. L.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Kang, X. S.(Nankai University, Tianjin 300071, China), Kavatsyuk, M.(KVI-CART, University of Groningen, NL-9747 AA Groningen, The Netherlands), Ke, B. C.(Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA), Kliemt, R.(Helmholtz Institute Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany), Kloss, B.(Johannes Gutenberg University of Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany), Kolcu, O. B.(Dogus University, 34722 Istanbul, Turkey), Kopf, B.(Bochum Ruhr-University, D-44780 Bochum, Germany), Kornicer, M.(University of Hawaii, Honolulu, Hawaii 96822, USA), Kuehn, W.(Justus Liebig University Giessen, II. Physikalisches Institut, Heinrich-Buff-Ring 16, D-35392 Giessen, Germany), Kupsc, A.(Uppsala University, Box 516, SE-75120 Uppsala, Sweden), Lai, W.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Lange, J. S.(Justus Liebig University Giessen, II. Physikalisches Institut, Heinrich-Buff-Ring 16, D-35392 Giessen, Germany), Lara, M.(Indiana University, Bloomington, Indiana 47405, USA), Larin, P.(Helmholtz Institute Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany), Li, C. H.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Li, Cheng(University of Science and Technology of China, Hefei 230026, China), Li, D. M.(Zhengzhou University, Zhengzhou 450001, China), Li, F.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Li, G.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Li, H. B.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Li, J. C.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Li, Jin(Seoul National University, Seoul, 151-747 Korea), Li, K.(Hangzhou Normal University, Hangzhou 310036, China), Li, K.(Shandong University, Jinan 250100, China), Li, P. R.(University of Chinese Academy of Sciences, Beijing 100049, China), Li, T.(Shandong University, Jinan 250100, China), Li, W. D.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Li, W. G.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Li, X. L.(Shandong University, Jinan 250100, China), Li, X. M.(Guangxi University, Nanning 530004, China), Li, X. N.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Li, X. Q.(Nankai University, Tianjin 300071, China), Li, Z. B.(Sun Yat-Sen University, Guangzhou 510275, China), Liang, H.(University of Science and Technology of China, Hefei 230026, China), Liang, Y. F.(Sichuan University, Chengdu 610064, China), Liang, Y. T.(Justus Liebig University Giessen, II. Physikalisches Institut, Heinrich-Buff-Ring 16, D-35392 Giessen, Germany), Liao, G. R.(Guangxi Normal University, Guilin 541004, China), Lin(Lin), D. X.(Helmholtz Institute Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany), Liu, B. J.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Liu, C. L.(Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA), Liu, C. X.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Liu, F. H.(Shanxi University, Taiyuan 030006, China), Liu, Fang(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Liu, Feng(Central China Normal University, Wuhan 430079, China), Liu, H. B.(Guangxi University, Nanning 530004, China), Liu, H. H.(Henan University of Science and Technology, Luoyang 471003, China), Liu, H. H.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Liu, H. M.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Liu, J.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Liu, J. P.(Wuhan University, Wuhan 430072, China), Liu, J. Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Liu, K.(Tsinghua University, Beijing 100084, China), Liu, K. Y.(Liaoning University, Shenyang 110036, China), Liu, L. D.(Peking University, Beijing 100871, China), Liu, P. L.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Liu, Q.(University of Chinese Academy of Sciences, Beijing 100049, China), Liu, S. B.(University of Science and Technology of China, Hefei 230026, China), Liu, X.(Lanzhou University, Lanzhou 730000, China), Liu, X. X.(University of Chinese Academy of Sciences, Beijing 100049, China), Liu, Y. B.(Nankai University, Tianjin 300071, China), Liu, Z. A.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Liu, Zhiqiang(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Liu, Zhiqing(Johannes Gutenberg University of Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany), Loehner, H.(KVI-CART, University of Groningen, NL-9747 AA Groningen, The Netherlands), Lou, X. C.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Lu, H. J.(Huangshan College, Huangshan 245000, China), Lu, J. G.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Lu, R. Q.(Hunan University, Changsha 410082, China), Lu, Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Lu, Y. P.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Luo, C. L.(Nanjing Normal University, Nanjing 210023, China), Luo, M. X.(Zhejiang University, Hangzhou 310027, China), Luo, T.(University of Hawaii, Honolulu, Hawaii 96822, USA), Luo, X. L.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Lv, M.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Lyu, X. R.(University of Chinese Academy of Sciences, Beijing 100049, China), Ma, F. C.(Liaoning University, Shenyang 110036, China), Ma, H. L.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Ma, L. L.(Shandong University, Jinan 250100, China), Ma, Q. M.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Ma, S.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Ma, T.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Ma, X. N.(Nankai University, Tianjin 300071, China), Ma, X. Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Maas, F. E.(Helmholtz Institute Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany), Maggiora, M.(University of Turin, I-10125, Turin, Italy), Malik, Q. A.(University of the Punjab, Lahore-54590, Pakistan), Mao, Y. J.(Peking University, Beijing 100871, China), Mao, Z. P.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Marcello, S.(University of Turin, I-10125, Turin, Italy), Messchendorp, J. G.(KVI-CART, University of Groningen, NL-9747 AA Groningen, The Netherlands), Min, J.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Min, T. J.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Mitchell, R. E.(Indiana University, Bloomington, Indiana 47405, USA), Mo, X. H.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Mo, Y. J.(Central China Normal University, Wuhan 430079, China), Morales, C. Morales(Helmholtz Institute Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany), Moriya, K.(Indiana University, Bloomington, Indiana 47405, USA), Muchnoi, N. Yu.(G.I. Budker Institute of Nuclear Physics SB RAS (BINP), Novosibirsk 630090, Russia), Muramatsu, H.(University of Minnesota, Minneapolis, Minnesota 55455, USA), Nefedov, Y.(Joint Institute for Nuclear Research, 141980 Dubna, Moscow region, Russia), Nerling, F.(Helmholtz Institute Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany), Nikolaev, I. B.(G.I. Budker Institute of Nuclear Physics SB RAS (BINP), Novosibirsk 630090, Russia), Ning, Z.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Nisar, S.(COMSATS Institute of Information Technology, Lahore, Defence Road, Off Raiwind Road, 54000 Lahore, Pakistan), Niu, S. L.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Niu, X. Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Olsen, S. L.(Seoul National University, Seoul, 151-747 Korea), Ouyang, Q.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Pacetti, S.(INFN and University of Perugia, I-06100, Perugia, Italy), Patteri, P.(INFN Laboratori Nazionali di Frascati, I-00044, Frascati, Italy), Pelizaeus, M.(Bochum Ruhr-University, D-44780 Bochum, Germany), Peng, H. P.(University of Science and Technology of China, Hefei 230026, China), Peters, K.(GSI Helmholtzcentre for Heavy Ion Research GmbH, D-64291 Darmstadt, Germany), Ping, J. L.(Nanjing Normal University, Nanjing 210023, China), Ping, R. G.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Poling, R.(University of Minnesota, Minneapolis, Minnesota 55455, USA), Pu, Y. N.(Hunan University, Changsha 410082, China), Qi, M.(Nanjing University, Nanjing 210093, China), Qian, S.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Qiao, C. F.(University of Chinese Academy of Sciences, Beijing 100049, China), Qin, L. Q.(Shandong University, Jinan 250100, China), Qin, N.(Wuhan University, Wuhan 430072, China), Qin, X. S.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Qin, Y.(Peking University, Beijing 100871, China), Qin, Z. H.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Qiu, J. F.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Rashid, K. H.(University of the Punjab, Lahore-54590, Pakistan), Redmer, C. F.(Johannes Gutenberg University of Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany), Ren, H. L.(Hunan University, Changsha 410082, China), Ripka, M.(Johannes Gutenberg University of Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany), Rong, G.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Ruan, X. D.(Guangxi University, Nanning 530004, China), Santoro, V.(INFN Sezione di Ferrara, I-44122, Ferrara, Italy), Sarantsev, A.(Joint Institute for Nuclear Research, 141980 Dubna, Moscow region, Russia), Savrié, M.(University of Ferrara, I-44122, Ferrara, Italy), Schoenning, K.(Uppsala University, Box 516, SE-75120 Uppsala, Sweden), Schumann, S.(Johannes Gutenberg University of Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany), Shan, W.(Peking University, Beijing 100871, China), Shao, M.(University of Science and Technology of China, Hefei 230026, China), Shen, C. P.(Beihang University, Beijing 100191, China), Shen, P. X.(Nankai University, Tianjin 300071, China), Shen, X. Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Sheng, H. Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Shepherd, M. R.(Indiana University, Bloomington, Indiana 47405, USA), Song, W. M.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Song, X. Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Sosio, S.(University of Turin, I-10125, Turin, Italy), Spataro, S.(University of Turin, I-10125, Turin, Italy), Spruck, B.(Justus Liebig University Giessen, II. Physikalisches Institut, Heinrich-Buff-Ring 16, D-35392 Giessen, Germany), Sun, G. X.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Sun, J. F.(Henan Normal University, Xinxiang 453007, China), Sun, S. S.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Sun, Y. J.(University of Science and Technology of China, Hefei 230026, China), Sun, Y. Z.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Sun, Z. J.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Sun, Z. T.(Indiana University, Bloomington, Indiana 47405, USA), Tang, C. J.(Sichuan University, Chengdu 610064, China), Tang, X.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Tapan, I.(Uludag University, 16059 Bursa, Turkey), Thorndike, E. H.(University of Rochester, Rochester, New York 14627, USA), Tiemens, M.(KVI-CART, University of Groningen, NL-9747 AA Groningen, The Netherlands), Toth, D.(University of Minnesota, Minneapolis, Minnesota 55455, USA), Ullrich, M.(Justus Liebig University Giessen, II. Physikalisches Institut, Heinrich-Buff-Ring 16, D-35392 Giessen, Germany), Uman, I.(Dogus University, 34722 Istanbul, Turkey), Varner, G. S.(University of Hawaii, Honolulu, Hawaii 96822, USA), Wang, B.(Nankai University, Tianjin 300071, China), Wang, B. L.(University of Chinese Academy of Sciences, Beijing 100049, China), Wang, D.(Peking University, Beijing 100871, China), Wang, D. Y.(Peking University, Beijing 100871, China), Wang, K.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Wang, L. L.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Wang, L. S.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Wang, M.(Shandong University, Jinan 250100, China), Wang, P.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Wang, P. L.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Wang, Q. J.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Wang, S. G.(Peking University, Beijing 100871, China), Wang, W.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Wang, X. F.(Tsinghua University, Beijing 100084, China), Wang(Yadi), Y. D.(INFN Laboratori Nazionali di Frascati, I-00044, Frascati, Italy), Wang, Y. F.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Wang, Y. Q.(Johannes Gutenberg University of Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany), Wang, Z.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Wang, Z. G.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Wang, Z. H.(University of Science and Technology of China, Hefei 230026, China), Wang, Z. Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Weber, T.(Johannes Gutenberg University of Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany), Wei, D. H.(Guangxi Normal University, Guilin 541004, China), Wei, J. B.(Peking University, Beijing 100871, China), Weidenkaff, P.(Johannes Gutenberg University of Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany), Wen, S. P.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Wiedner, U.(Bochum Ruhr-University, D-44780 Bochum, Germany), Wolke, M.(Uppsala University, Box 516, SE-75120 Uppsala, Sweden), Wu, L. H.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Wu, Z.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Xia, L. G.(Tsinghua University, Beijing 100084, China), Xia, Y.(Hunan University, Changsha 410082, China), Xiao, D.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Xiao, Z. J.(Nanjing Normal University, Nanjing 210023, China), Xie, Y. G.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Xu, G. F.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Xu, L.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Xu, Q. J.(Hangzhou Normal University, Hangzhou 310036, China), Xu, Q. N.(University of Chinese Academy of Sciences, Beijing 100049, China), Xu, X. P.(Soochow University, Suzhou 215006, China), Yan, L.(University of Science and Technology of China, Hefei 230026, China), Yan, W. B.(University of Science and Technology of China, Hefei 230026, China), Yan, W. C.(University of Science and Technology of China, Hefei 230026, China), Yan, Y. H.(Hunan University, Changsha 410082, China), Yang, H. X.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Yang, L.(Wuhan University, Wuhan 430072, China), Yang, Y.(Central China Normal University, Wuhan 430079, China), Yang, Y. X.(Guangxi Normal University, Guilin 541004, China), Ye, H.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Ye, M.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Ye, M. H.(China Center of Advanced Science and Technology, Beijing 100190, China), Yin, J. H.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Yu, B. X.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Yu, C. X.(Nankai University, Tianjin 300071, China), Yu, H. W.(Peking University, Beijing 100871, China), Yu, J. S.(Lanzhou University, Lanzhou 730000, China), Yuan, C. Z.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Yuan, W. L.(Nanjing University, Nanjing 210093, China), Yuan, Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Yuncu, A.(Dogus University, 34722 Istanbul, Turkey), Zafar, A. A.(University of the Punjab, Lahore-54590, Pakistan), Zallo, A.(INFN Laboratori Nazionali di Frascati, I-00044, Frascati, Italy), Zeng, Y.(Hunan University, Changsha 410082, China), Zhang, B. X.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhang, B. Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhang, C.(Nanjing University, Nanjing 210093, China), Zhang, C. C.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhang, D. H.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhang, H. H.(Sun Yat-Sen University, Guangzhou 510275, China), Zhang, H. Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhang, J. J.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhang, J. L.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhang, J. Q.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhang, J. W.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhang, J. Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhang, J. Z.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhang, K.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhang, L.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhang, S. H.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhang, X. Y.(Shandong University, Jinan 250100, China), Zhang, Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhang, Y. H.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhang, Y. T.(University of Science and Technology of China, Hefei 230026, China), Zhang, Z. H.(Central China Normal University, Wuhan 430079, China), Zhang, Z. P.(University of Science and Technology of China, Hefei 230026, China), Zhang, Z. Y.(Wuhan University, Wuhan 430072, China), Zhao, G.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhao, J. W.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhao, J. Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhao, J. Z.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhao, Lei(University of Science and Technology of China, Hefei 230026, China), Zhao, Ling(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhao, M. G.(Nankai University, Tianjin 300071, China), Zhao, Q.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhao, Q. W.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhao, S. J.(Zhengzhou University, Zhengzhou 450001, China), Zhao, T. C.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhao, Y. B.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhao, Z. G.(University of Science and Technology of China, Hefei 230026, China), Zhemchugov, A.(Joint Institute for Nuclear Research, 141980 Dubna, Moscow region, Russia), Zheng, B.(University of South China, Hengyang 421001, China), Zheng, J. P.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zheng, W. J.(Shandong University, Jinan 250100, China), Zheng, Y. H.(University of Chinese Academy of Sciences, Beijing 100049, China), Zhong, B.(Nanjing Normal University, Nanjing 210023, China), Zhou, L.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhou, Li(Nankai University, Tianjin 300071, China), Zhou, X.(Wuhan University, Wuhan 430072, China), Zhou, X. K.(University of Science and Technology of China, Hefei 230026, China), Zhou, X. R.(University of Science and Technology of China, Hefei 230026, China), Zhou, X. Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhu, K.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhu, K. J.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhu, S.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhu, X. L.(Tsinghua University, Beijing 100084, China), Zhu, Y. C.(University of Science and Technology of China, Hefei 230026, China), Zhu, Y. S.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhu, Z. A.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zhuang, J.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), Zou, B. S.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China), and Zou, J. H.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China)

Abstract

Using data samples collected at center-of-mass energies of √s = 4.009, 4.230, 4.260, and 4.360 GeV with the BESIII detector operating at the BEPCII collider, we perform a search for the process e+e− → γχcJ (J=0, 1, 2) and find evidence for e+e− → γχc1 and e+e− → γχc2 with statistical significances of 3.0σ and 3.4σ, respectively. The Born cross sections σB(e+e− → γχcJ), as well as their upper limits at the 90% confidence level (C.L.) are determined at each center-of-mass energy.

Published
2015

23. The architectonic fold similarity network in protein fold space

Author

Zhun-Zhi Jin, W. Guan, Xiufen Zou, and Z.-B. Sun

Subjects
Random graph, Quantitative Biology::Biomolecules, Computer Science::Information Retrieval, Structure (category theory), Condensed Matter Physics, Space (mathematics), Degree distribution, Topology, Electronic, Optical and Magnetic Materials, Divergent evolution, Similarity (network science), Feature (machine learning), Evolutionary dynamics, Mathematics
Abstract

By constructing the fold similarity network (FSN), we present an alternative approach to the characteristic and architecture of protein fold space. The degree distribution P(k) of FSN differs far from that of the random network with the same number of nodes and connections. The investigation shows that FSN possesses small-world property and broad-scale feature. In order to access to the assumption of the dynamics behavior for FSN, we design a simple evolutionary dynamics model based on the duplication and variation fashions of protein folds. The simulation network generated by this model is a small-world one and reproduces the broad-scale degree distribution consistent with that of FSN. It seems that this model can be used to depict the divergent evolution and expanding progress of protein fold space.

Published
2006

24. Icariin may benefit the mesenchymal stem cells of patients with steroid-associated osteonecrosis by ABCB1-promoter demethylation: a preliminary study

Author

H. Xiao, W.-S. Kan, F.-B. Mo, Z.-B. Sun, S. Hu, J.-W. Wang, Q.-S. Zhang, and S.-N. Ye

Subjects
Adult, Male, medicine.medical_specialty, ATP Binding Cassette Transporter, Subfamily B, Cell Survival, Endocrinology, Diabetes and Metabolism, Cellular differentiation, Drug Evaluation, Preclinical, medicine.disease_cause, Epigenesis, Genetic, chemistry.chemical_compound, Femur Head Necrosis, Osteogenesis, Internal medicine, Medicine, Humans, Viability assay, Molecular Targeted Therapy, Promoter Regions, Genetic, Glucocorticoids, Cells, Cultured, Aged, Flavonoids, Membrane Potential, Mitochondrial, Adipogenesis, business.industry, Mesenchymal stem cell, Cell Differentiation, Mesenchymal Stem Cells, DNA Methylation, Middle Aged, Endocrinology, medicine.anatomical_structure, chemistry, DNA methylation, Female, Bone marrow, business, Reactive Oxygen Species, Icariin, Oxidative stress, Drugs, Chinese Herbal
Abstract

In this study, we found out a previously undefined function of icariin which restored the dynamic balance between osteogenic and adipogenic differentiation of mesenchymal stem cells (MSCs) in patients with osteonecrosis of femoral head (ONFH) via ABCB1-promoter demethylation. These findings provided important information regarding potential implication of icariin targeting epigenetic changes for the treatment of steroid -associated ONFH. Here, we investigated whether icariin can also exert a beneficial role in the reactivation of MSCs in the patients with steroid-associated ONFH via ABCB1-promoter demethylation. Bone marrow was collected from the proximal femur in patients with steroid-associated ONFH (n = 20) and patients with new femoral neck fractures (n = 22), and then MSCs were isolated. We investigated cell viability, intracellular reactive oxygen species (ROS) level, mitochondrial membrane potential (MMP), P-glycoprotein (P-gp) activity, the transcript levels of ABCB1 and oxidative stress-related genes, methylation extent at CpG islands of ABCB1 promoter, and osteogenic and adipogenic differentiation ability of MSCs from the femoral neck fractures group and from the steroid-associated ONFH group treated with or without icariin. We observed that MSCs from the steroid-associated ONFH group showed reduced proliferation ability, elevated ROS level, depressed MMP, weakened osteogenesis, and enhanced adipogenesis while low P-gp activity, transcription level of ABCB1, and oxidative stress-related genes as well as aberrant CpG islands hypermethylation of ABCB1 were also noted in steroid-associated ONFH group. Treatment with icariin obviously induced de novo P-gp expression, decreased oxidative stress, and promoted osteogenesis. Icariin may be a potential drug targeting epigenetic changes for the treatment of steroid-associated ONFH.

Published
2014

25. SCIRR39 promotes neurite extension via RhoA in NGF-induced PC12 cells

Author

J W Yang, C. F. Zhao, S J Liu, Z B Sun, Y Liu, Y L Ni, and H D Hui

Subjects
RHOA, Cellular differentiation, PC12 Cells, Flow cytometry, Small hairpin RNA, FYN, Developmental Neuroscience, Downregulation and upregulation, Nerve Growth Factor, medicine, Neurites, Animals, Phosphorylation, Cell Proliferation, Neurons, biology, medicine.diagnostic_test, Cell growth, Cell Cycle, Cell Differentiation, Cell cycle, Molecular biology, Cell biology, Rats, Up-Regulation, Neurology, biology.protein, Carrier Proteins, rhoA GTP-Binding Protein, Signal Transduction
Abstract

SCIRR39 is an identified upregulated gene in rat primary neuron injury and/or regeneration process with roles largely unexplored. Using real-time quantitative PCR, Western blotting and immunofluorescence, SCIRR39 expression was detected in normal PC12 cells and upregulated in differentiated cells. The results of cell proliferation by Cell Counting Kit and cell cycle by flow cytometry indicated that SCIRR39 inhibited cell proliferation and induced the decrease in S phase. Importantly, immunofluorescent and RhoA pull-down assays showed that SCIRR39 strongly affected the neurite extension of NGF-treated PC12 cells through a RhoA-dependent mechanism, but the truncated mutants of SCIRR39 containing a truncation from 141AA to 211AA or from 397AA to 424AA failed to mock the SCIRR39 effect on neurite extension. Moreover, change of SCIRR39 expression in NGF-treated PC12 cells regulated the expression and phosphorylation of Fyn, a regulator of RhoA activity, but not the expression of ROCK II protein. Finally, immunofluorescence and RhoA pull-down assays revealed that obvious inhibition of neurite extension by SCIRR39 shRNA was reversed by RhoA inhibitor C3-transferase. Our results indicated that SCIRR39 increased the neurite extension in NGF-treated PC12 cells via RhoA, suggesting that SCIRR39 contributes to the regeneration of neuron injury by specifically altering the differentiation program.

Published
2012

26. The possible hidden-charm molecular baryons composed of anti-charmed meson and charmed baryon

Author

Xiang Liu, Zhong-Cheng Yang, Jun He, Z. B. Sun, and Shi-Lin Zhu

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson, Nuclear Theory, High Energy Physics::Phenomenology, FOS: Physical sciences, Astronomy and Astrophysics, High Energy Physics - Experiment, Baryon, Nuclear Theory (nucl-th), High Energy Physics - Phenomenology, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), High Energy Physics::Experiment, Charm (quantum number), Nuclear Experiment (nucl-ex), Nuclear Experiment, Instrumentation, Nuclear theory
Abstract

With the one-boson-exchange model we have studied the possible existence of the very loosely bound hidden-charm molecular baryons composed of anti-charmed meson and charmed baryon. Our numerical results indicate that there exist $\Sigma_c\bar{D}^*$ states with $I(J^P)=1/2(1/2^-), 1/2(3/2^-), 3/2(1/2^-), 3/2(3/2^-)$ and $\Sigma_c\bar{D}$ state with $3/2(1/2^-)$. But the $\Lambda_c \bar{D}$ and $\Lambda_c \bar{D}^*$ molecular states do not exist., Comment: 8 pages, 2 tables, 3 figures. Matches version accepted for publication in Chinese Physics C

Published
2011
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28. The Variations of Flow Stress and Coercivity of Dual Phase Steel during the Reverse Flow

Author

M. T. Ma and Z. B. Sun

Subjects
Back stress, Materials science, Flow curve, Dual-phase steel, Flow (mathematics), Inflection point, Metallurgy, Mechanics, Flow stress, Coercivity
Abstract

The variations of flow stress and coercivity of dual phase steel during the reverse flow followed prestrain have been investigated. The results show that the variational curves of coercivity during the reverse flow cam be divided into three domains. The reverse flow curves analysed by using of Hollomon’s equation with computer have two inflexion points. The relation between coercivity variational curves and reverse flow curves and the case of variation of coercivity due to reverse strain have been analysed. The importance of the results in practice, the method for measuring variation of back stress in dual phase steel were discussed and suggested.

Published
1986

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