Evidence of Cosmic-Ray Acceleration up to Sub-PeV Energies in the Supernova Remnant IC 443

Issued Date

2026-04-24

Resource Type

Article

ISSN

00319007

eISSN

10797114

DOI

10.1103/pxn6-qzhz

Scopus ID

2-s2.0-105037453634

Journal Title

Physical Review Letters

Volume

136

Issue

16

Rights Holder(s)

SCOPUS

Bibliographic Citation

Physical Review Letters Vol.136 No.16 (2026)

Suggested Citation

Cao Z., Aharonian F., Bai Y.X., Bao Y.W., Bastieri D., Bi X.J., Bi Y.J., Bian W., Bukevich A.V., Cai C.M., Cao W.Y., Cao Z., Chang J., Chang J.F., Chen A.M., Chen E.S., Chen G.H., Chen H.X., Chen L., Chen L., Chen M.J., Chen M.L., Chen Q.H., Chen S., Chen S.H., Chen S.Z., Chen T.L., Chen X.B., Chen X.J., Chen Y., Cheng N., Cheng Y.D., Chu M.C., Cui M.Y., Cui S.W., Cui X.H., Cui Y.D., Dai B.Z., Dai H.L., Dai Z.G., Danzengluobu, Diao Y.X., Dong X.Q., Duan K.K., Fan J.H., Fan Y.Z., Fang J., Fang J.H., Fang K., Feng C.F., Feng H., Feng L., Feng S.H., Feng X.T., Feng Y., Feng Y.L., Gabici S., Gao B., Gao C.D., Gao Q., Gao W., Gao W.K., Ge M.M., Ge T.T., Geng L.S., Giacinti G., Gong G.H., Gou Q.B., Gu M.H., Guo F.L., Guo J., Guo X.L., Guo Y.Q., Guo Y.Y., Han Y.A., Hannuksela O.A., Hasan M., He H.H., He H.N., He J.Y., He X.Y., He Y., Hernández-Cadena S., Hou B.W., Hou C., Hou X., Hu H.B., Hu S.C., Huang C., Huang D.H., Huang J.J., Huang T.Q., Huang W.J., Huang X.T., Huang X.Y., Huang Y., Huang Y.Y., Ji X.L., Jia H.Y., Jia K. Evidence of Cosmic-Ray Acceleration up to Sub-PeV Energies in the Supernova Remnant IC 443. Physical Review Letters Vol.136 No.16 (2026). doi:10.1103/pxn6-qzhz Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/116595

Title

Evidence of Cosmic-Ray Acceleration up to Sub-PeV Energies in the Supernova Remnant IC 443

Author(s)

Cao Z.
 Aharonian F.
 Bai Y.X.
 Bao Y.W.
 Bastieri D.
 Bi X.J.
 Bi Y.J.
 Bian W.
 Bukevich A.V.
 Cai C.M.
 Cao W.Y.
 Cao Z.
 Chang J.
 Chang J.F.
 Chen A.M.
 Chen E.S.
 Chen G.H.
 Chen H.X.
 Chen L.
 Chen L.
 Chen M.J.
 Chen M.L.
 Chen Q.H.
 Chen S.
 Chen S.H.
 Chen S.Z.
 Chen T.L.
 Chen X.B.
 Chen X.J.
 Chen Y.
 Cheng N.
 Cheng Y.D.
 Chu M.C.
 Cui M.Y.
 Cui S.W.
 Cui X.H.
 Cui Y.D.
 Dai B.Z.
 Dai H.L.
 Dai Z.G.
 Danzengluobu
 Diao Y.X.
 Dong X.Q.
 Duan K.K.
 Fan J.H.
 Fan Y.Z.
 Fang J.
 Fang J.H.
 Fang K.
 Feng C.F.
 Feng H.
 Feng L.
 Feng S.H.
 Feng X.T.
 Feng Y.
 Feng Y.L.
 Gabici S.
 Gao B.
 Gao C.D.
 Gao Q.
 Gao W.
 Gao W.K.
 Ge M.M.
 Ge T.T.
 Geng L.S.
 Giacinti G.
 Gong G.H.
 Gou Q.B.
 Gu M.H.
 Guo F.L.
 Guo J.
 Guo X.L.
 Guo Y.Q.
 Guo Y.Y.
 Han Y.A.
 Hannuksela O.A.
 Hasan M.
 He H.H.
 He H.N.
 He J.Y.
 He X.Y.
 He Y.
 Hernández-Cadena S.
 Hou B.W.
 Hou C.
 Hou X.
 Hu H.B.
 Hu S.C.
 Huang C.
 Huang D.H.
 Huang J.J.
 Huang T.Q.
 Huang W.J.
 Huang X.T.
 Huang X.Y.
 Huang Y.
 Huang Y.Y.
 Ji X.L.
 Jia H.Y.
 Jia K.

Author's Affiliation

University of Chinese Academy of Sciences
 Tsinghua University
 Shanghai Jiao Tong University
 Sun Yat-Sen University
 Université Paris Cité
 University of Science and Technology of China
 Shandong University
 Nanjing University
 Chinese University of Hong Kong
 Zhengzhou University
 Southwest Jiaotong University
 Yunnan University
 Guangzhou University
 Institute of High Energy Physics, Chinese Academy of Sciences
 National Astronomical Observatories Chinese Academy of Sciences
 Hebei Normal University
 Max-Planck-Institut für Kernphysik
 Institute for Nuclear Research of the Russian Academy of Sciences
 Yerevan State University
 China Center of Advanced Science and Technology World Laboratory
 Zhejiang Lab
 Purple Mountain Observatory Chinese Academy of Sciences
 Shanghai Astronomical Observatory Chinese Academy of Sciences
 Yunnan Observatories
 Tibet University
 State Key Laboratory of Particle Detection & Electronics
 TIANFU Cosmic Ray Research Center

Corresponding Author(s)

Cao Z.

Other Contributor(s)

Mahidol University

Abstract

Supernova remnants (SNRs) have been considered as the primary contributors to cosmic rays (CRs) in our Galaxy. However, the maximum energy of particles that can be accelerated by shocks of SNRs is uncertain, and SNRs' contribution to CRs around PeV energies is unclear. In this Letter, we present observations of high-energy γ-ray emission from the SNR IC 443 using the Large High Altitude Air Shower Observatory (LHAASO). The morphological analysis reveals a pointlike source whose location and spectrum are consistent with those of the Fermi-LAT-detected compact source with π0-decay signature, and a more extended source that is associated with a newly discovered Fermi source. The spectrum of the point source can be described by a power-law function with an index of ∼3.0, extending beyond ∼30 TeV without apparent cutoff. Assuming a hadronic origin of the γ-ray emission, the 95% lower limit of accelerated protons reaches about 300 TeV. The extended source might be associated with IC 443, SNR G189.6+3.3, or the putative pulsar wind nebula CXOU J061705.3+222127, and can be explained by either a hadronic or a leptonic model with particles reaching hundreds of TeV. These LHAASO results provide compelling evidence that sub-PeV CRs can be accelerated efficiently by shocks of SNRs.

Keyword(s)

Physics and Astronomy

Availability

URI

https://repository.li.mahidol.ac.th/handle/123456789/116595

Collections

Scopus 2026