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

Issued Date

2024-11-01

Resource Type

Article

ISSN

20418205

eISSN

20418213

DOI

10.3847/2041-8213/ad8921

Scopus ID

2-s2.0-85209091047

Journal Title

Astrophysical Journal Letters

Volume

975

Issue

2

Rights Holder(s)

SCOPUS

Bibliographic Citation

Astrophysical Journal Letters Vol.975 No.2 (2024)

Suggested Citation

Cao Z., Aharonian F., Axikegu, Bai Y.X., Bao Y.W., Bastieri D., Bi X.J., Bi Y.J., Bian W., Bukevich A.V., Cao Q., Cao W.Y., Cao Z., Chang J., Chang J.F., Chen A.M., Chen E.S., Chen H.X., Chen L., 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 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, 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 Y., Hor Y.K., Hou B.W., Hou C., Hou X., Hu H.B., Hu Q., Hu S.C., Huang C., Huang D.H., 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., Jiang H.B., Jiang K., Jiang X.W. Detection of Very High-energy Gamma-Ray Emission from the Radio Galaxy M87 with LHAASO. Astrophysical Journal Letters Vol.975 No.2 (2024). doi:10.3847/2041-8213/ad8921 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/102108

Title

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

Author(s)

Cao Z.
 Aharonian F.
 Axikegu
 Bai Y.X.
 Bao Y.W.
 Bastieri D.
 Bi X.J.
 Bi Y.J.
 Bian W.
 Bukevich A.V.
 Cao Q.
 Cao W.Y.
 Cao Z.
 Chang J.
 Chang J.F.
 Chen A.M.
 Chen E.S.
 Chen H.X.
 Chen L.
 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 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
 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 Y.
 Hor Y.K.
 Hou B.W.
 Hou C.
 Hou X.
 Hu H.B.
 Hu Q.
 Hu S.C.
 Huang C.
 Huang D.H.
 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.
 Jiang H.B.
 Jiang K.
 Jiang X.W.

Author's Affiliation

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

Corresponding Author(s)

Cao Z.

Other Contributor(s)

Mahidol University

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 ∼ 9σ. 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 τ r rise = 1.05 ± 0.49 days and decay time of τ d decay = 2.17 ± 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 × 1015 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.

Keyword(s)

Earth and Planetary Sciences
 Physics and Astronomy

Availability

URI

https://repository.li.mahidol.ac.th/handle/20.500.14594/102108

Collections

Scopus 2024