Ultrahigh-energy gamma-ray emission associated with black hole-jet systems.
Z. Cao, F Aharonian, Yun-Xiang Bai, Yi-Wei Bao, D. Bastieri, X. J. Bi, Yujiang Bi, Wen-Yi Bian, A.V Bukevich, Chengmiao Cai, Wen-Yu Cao, Zhe Cao, Jin Chang, J. F. Chang, Aming Chen, En-Sheng Chen, Guohua Chen, H X Chen, Liang Chen, Long Chen, Ming-Jun Chen, Ma-Li Chen, Qi Chen, Shi Chen, Su-Hong Chen, S Z Chen, T. L. Chen, X B Chen, Xuejian Chen, Y. Chen, Ning Cheng, Yaodong Cheng, M. C. Chu, Mingyue Cui, S. W. Cui, Xiaohong Cui, Yudong Cui, B Z Dai, H. L. Dai, Zi-Gao Dai, Danzengluobu Danzengluobu, Yang-Xuan Diao, Xu-Qiang Dong, Kai-Kai Duan, Jun-Hui Fan, Yi-Zhong Fan, Jun Fang, Jian-Hua Fang, Kun Fang, Cun-Feng Feng, Hua Feng, Li Feng, Shaohui Feng, Xia‐Ting Feng, Y. Feng, Yuzhen Feng, S. Gabici, B. S. Gao, Chuyue Gao, Qi Gao, Wei Gao, Wei-Kang Gao, M. M. Ge, Tianyu Ge, Lisi Geng, Gwenael Giacinti, G. Gong, Q. B. Gou, M. H. Gu, Fu-Lai Guo, Jing Guo, Xiao-Lei Guo, Yi-Qing Guo, Ying-Ying Guo, Yi-Ang Han, O. A. Hannuksela, M. Zahid Hasan, H. H. He, Haoning He, Jianying He, Xing‐Xiang He, Yu He, S. Hernández-Cadena, Bo-Wen Hou, C. Hou, Xian Hou, H. B. Hu, Sheng Hu, Chen Huang, Dai-Hui Huang, Jiajun Huang, Tian-Qi Huang, Wen-Jun Huang, Xing-Tao Huang, Xiaoyuan Huang, Y. Huang, Yi-Yun Huang, X. L. Ji, H. Y. Jia, Kang Jia
Abstract
Black holes (BHs), one of the most intriguing objects in the universe, can manifest themselves through electromagnetic radiation initiated by the accretion flow. Some stellar-mass BHs drive relativistic jets when accreting matter from their companion stars, forming microquasars. Non-thermal emission from the radio to teraelectronvolt gamma-ray band has been observed from microquasars, indicating the acceleration of relativistic particles. Here we report detection of four microquasars (SS 433, V4641 Sgr, GRS 1915+105, MAXI J1820+070) of spectra extending to the ultrahigh-energy (UHE; photon energy [Formula: see text] TeV) band, and one microquasar (Cygnus X-1) with a spectrum approaching 100 TeV, using the Large High Altitude Air Shower Observatory. Notably, the total emission associated with SS 433 cannot be interpreted with a single leptonic component. In the UHE band, its emission is in spatial coincidence with a giant atomic cloud, which is consistent with a hadronic origin. An elongated source is discovered from V4641 Sgr with the spectrum continuing up to 800 TeV. The detection of UHE gamma rays demonstrates that accreting BHs and their environments can operate as extremely efficient accelerators of particles up to 1 PeV, suggesting that microquasars are important contributors to Galactic cosmic rays, especially around the 'knee' region.