Ultra-high-energy $\gamma$-ray imprints from PeV particles accelerated by supernova remnants
Abstract
The quest for the origin of cosmic ray (CRs) is a fundamental issue in astrophysics. Shocks of supernova remnants (SNRs) have been considered as the dominant contributors to Galactic CRs below the spectral knee near petaelectronvolt (PeV). Whether SNRs are efficient accelerators of particles beyond PeV energies has long been debated. Here we report observations of very-high-energy -ray emission up to hundreds of TeV from two middle age shell-type SNRs, G150.34.5 and -Cygni, with the Large High Altitude Air Shower Observatory (LHAASO). Two (or three) distinct morphological/spectral components with convex spectral shapes are observed in both sources, with the low-energy one being more extended than the high-energy one. %Although it is possible that these high-energy components may be driven by powerful pulsars, The likely association of the high-energy component with molecular clouds at similar distances, and the weakness/absence of pulsar wind nebulae (PWNe) inside these SNRs clearly indicate for the first time that the highest energy emission is produced by collision of hadronic CRs up to PeV energies with the clouds. These results are compatible with the classic model prediction that PeV particles accelerated near the end of the free expansion phase of SNR evolution can illuminate nearby molecular clouds (MCs) to produce strong -ray emission.
Cite
@article{arxiv.2604.22621,
title = {Ultra-high-energy $\gamma$-ray imprints from PeV particles accelerated by supernova remnants},
author = {Zhen Cao and F. Aharonian and Y. X. Bai and Y. W. Bao and D. Bastieri and X. J. Bi and Y. J. Bi and W. Bian and J. Blunier and A. V. Bukevich and C. M. Cai and Y. Y. Cai and W. Y. Cao and Zhe Cao and J. Chang and J. F. Chang and E. S. Chen and G. H. Chen and H. K. Chen and L. F. Chen and Liang Chen and Long Chen and M. J. Chen and M. L. Chen and Q. H. Chen and S. Chen and S. H. Chen and S. Z. Chen and T. L. Chen and X. B. Chen and X. J. Chen and X. P. Chen and Y. Chen and N. Cheng and Q. Y. Cheng and Y. D. Cheng and M. Y. Cui and S. W. Cui and X. H. Cui and Y. D. Cui and B. Z. Dai and H. L. Dai and Z. G. Dai and Danzengluobu and Y. X. Diao and A. J. Dong and X. Q. Dong and K. K. Duan and J. H. Fan and Y. Z. Fan and J. Fang and J. H. Fang and K. Fang and C. F. Feng and H. Feng and L. Feng and S. H. Feng and X. T. Feng and Y. Feng and Y. L. Feng and S. Gabici and B. Gao and Q. Gao and W. Gao and W. K. Gao and M. M. Ge and T. T. Ge and L. S. Geng and G. Giacinti and G. H. Gong and Q. B. Gou and M. H. Gu and F. L. Guo and J. Guo and K. J. Guo and X. L. Guo and Y. Q. Guo and Y. Y. Guo and R. P. Han and O. A. Hannuksela and M. Hasan and H. H. He and H. N. He and J. Y. He and X. Y. He and Y. He and S. Hernández-Cadena and B. W. Hou and C. Hou and X. Hou and H. B. Hu and S. C. Hu and C. Huang and D. H. Huang and J. J. Huang and X. L. Huang and X. T. Huang and X. Y. Huang and Y. Huang and Y. Y. Huang and A. Inventar and X. L. Ji and H. Y. Jia and K. Jia and H. B. Jiang and K. Jiang and X. W. Jiang and Z. J. Jiang and M. Jin and S. Kaci and M. M. Kang and I. Karpikov and D. Khangulyan and D. Kuleshov and K. Kurinov and Cheng Li and Cong Li and D. Li and F. Li and H. B. Li and H. C. Li and Jian Li and Jie Li and K. Li and L. Li and R. L. Li and S. D. Li and T. Y. Li and W. L. Li and X. R. Li and Y. Li and Zhe Li and Zhuo Li and E. W. Liang and Y. F. Liang and S. J. Lin and B. Liu and C. Liu and D. Liu and D. B. Liu and H. Liu and J. Liu and J. L. Liu and J. R. Liu and M. Y. Liu and R. Y. Liu and S. M. Liu and W. Liu and X. Liu and Y. Liu and Y. Liu and Y. N. Liu and Y. Q. Lou and Q. Luo and Y. Luo and H. K. Lv and B. Q. Ma and L. L. Ma and X. H. Ma and I. O. Maliy and J. R. Mao and Z. Min and W. Mitthumsiri and Y. Mizuno and G. B. Mou and A. Neronov and K. C. Y. Ng and M. Y. Ni and L. Nie and L. J. Ou and Z. W. Ou and P. Pattarakijwanich and Z. Y. Pei and D. Y. Peng and J. C. Qi and M. Y. Qi and J. J. Qin and D. Qu and A. Raza and C. Y. Ren and D. Ruffolo and A. Sáiz and D. Savchenko and D. Semikoz and L. Shao and O. Shchegolev and Y. Z. Shen and X. D. Sheng and Z. D. Shi and F. W. Shu and H. C. Song and Yu. V. Stenkin and Y. Su and D. X. Sun and H. Sun and J. X. Sun and Q. N. Sun and X. N. Sun and Z. B. Sun and N. H. Tabasam and J. Takata and P. H. T. Tam and H. B. Tan and Q. W. Tang and R. Tang and Z. B. Tang and W. W. Tian and C. N. Tong and L. H. Wan and C. Wang and D. H. Wang and G. W. Wang and H. G. Wang and J. C. Wang and K. Wang and Kai Wang and Kai Wang and L. P. Wang and L. Y. Wang and L. Y. Wang and R. Wang and W. Wang and X. G. Wang and X. J. Wang and X. Y. Wang and Y. Wang and Y. D. Wang and Z. H. Wang and Z. X. Wang and Zheng Wang and D. M. Wei and J. J. Wei and Y. J. Wei and T. Wen and S. S. Weng and C. Y. Wu and H. R. Wu and Q. W. Wu and S. Wu and X. F. Wu and Y. S. Wu and S. Q. Xi and J. Xia and J. J. Xia and G. M. Xiang and D. X. Xiao and G. Xiao and Y. F. Xiao and Y. L. Xin and H. D. Xing and Y. Xing and D. R. Xiong and B. N. Xu and C. Y. Xu and D. L. Xu and R. F. Xu and R. X. Xu and S. S. Xu and W. L. Xu and L. Xue and D. H. Yan and T. Yan and C. W. Yang and C. Y. Yang and F. F. Yang and L. L. Yang and M. J. Yang and R. Z. Yang and W. X. Yang and Z. H. Yang and Z. G. Yao and X. A. Ye and L. Q. Yin and N. Yin and X. H. You and Z. Y. You and Q. Yuan and H. Yue and H. D. Zeng and T. X. Zeng and W. Zeng and X. T. Zeng and M. Zha and B. B. Zhang and B. T. Zhang and C. Zhang and H. Zhang and H. M. Zhang and H. Y. Zhang and J. L. Zhang and J. Y. Zhang and Li Zhang and P. F. Zhang and R. Zhang and S. R. Zhang and S. S. Zhang and S. Y. Zhang and W. Zhang and W. Y. Zhang and X. Zhang and X. P. Zhang and Yi Zhang and Yong Zhang and Z. P. Zhang and J. Zhao and L. Zhao and L. Z. Zhao and S. P. Zhao and X. H. Zhao and Z. H. Zhao and F. Zheng and T. C. Zheng and B. Zhou and H. Zhou and J. N. Zhou and M. Zhou and P. Zhou and R. Zhou and X. X. Zhou and X. X. Zhou and B. Y. Zhu and C. G. Zhu and F. R. Zhu and H. Zhu and K. J. Zhu and Y. C. Zou and X. Zuo and Y. Li},
journal= {arXiv preprint arXiv:2604.22621},
year = {2026}
}
Comments
31 pages, 8 figures, 3 Tables