Measurement of Ultra-High-Energy Diffuse Gamma-Ray Emission of the Galactic Plane from 10 TeV to 1 PeV with LHAASO-KM2A

Issued Date

2023-10-13

Resource Type

Article

eISSN

10797114

DOI

10.1103/PhysRevLett.131.151001

Scopus ID

2-s2.0-85175276512

Pubmed ID

37897763

Journal Title

Physical review letters

Volume

131

Issue

15

Rights Holder(s)

SCOPUS

Bibliographic Citation

Physical review letters Vol.131 No.15 (2023) , 151001

Suggested Citation

Cao Z., Aharonian F., An Q., Axikegu, Bai Y.X., Bao Y.W., Bastieri D., Bi X.J., Bi Y.J., Cai J.T., Cao Q., Cao W.Y., Cao Z., Chang J., Chang J.F., Chen A.M., Chen E.S., Chen L., Chen L., Chen L., Chen M.J., Chen M.L., Chen Q.H., Chen S.H., Chen S.Z., Chen T.L., Chen Y., Cheng N., Cheng Y.D., Cui M.Y., Cui S.W., Cui X.H., Cui Y.D., Dai B.Z., Dai H.L., Dai Z.G., Danzengluobu, Della Volpe D., Dong X.Q., Duan K.K., Fan J.H., Fan Y.Z., Fang J., Fang K., Feng C.F., Feng L., Feng S.H., Feng X.T., Feng Y.L., Gabici S., Gao B., Gao C.D., Gao L.Q., Gao Q., Gao W., Gao W.K., Ge M.M., Geng L.S., Giacinti G., Gong G.H., Gou Q.B., Gu M.H., Guo F.L., Guo X.L., Guo Y.Q., Guo Y.Y., Han Y.A., He H.H., He H.N., He J.Y., He X.B., He Y., Heller M., Hor Y.K., Hou B.W., Hou C., Hou X., Hu H.B., Hu Q., Hu S.C., Huang D.H., Huang T.Q., Huang W.J., Huang X.T., Huang X.Y., Huang Y., Huang Z.C., Ji X.L., Jia H.Y., Jia K., Jiang K., Jiang X.W., Jiang Z.J., Jin M., Kang M.M., Ke T., Kuleshov D., Kurinov K., Li B.B., Li C. Measurement of Ultra-High-Energy Diffuse Gamma-Ray Emission of the Galactic Plane from 10 TeV to 1 PeV with LHAASO-KM2A. Physical review letters Vol.131 No.15 (2023) , 151001. doi:10.1103/PhysRevLett.131.151001 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/90978

Title

Measurement of Ultra-High-Energy Diffuse Gamma-Ray Emission of the Galactic Plane from 10 TeV to 1 PeV with LHAASO-KM2A

Author(s)

Cao Z.
 Aharonian F.
 An Q.
 Axikegu
 Bai Y.X.
 Bao Y.W.
 Bastieri D.
 Bi X.J.
 Bi Y.J.
 Cai J.T.
 Cao Q.
 Cao W.Y.
 Cao Z.
 Chang J.
 Chang J.F.
 Chen A.M.
 Chen E.S.
 Chen L.
 Chen L.
 Chen L.
 Chen M.J.
 Chen M.L.
 Chen Q.H.
 Chen S.H.
 Chen S.Z.
 Chen T.L.
 Chen Y.
 Cheng N.
 Cheng Y.D.
 Cui M.Y.
 Cui S.W.
 Cui X.H.
 Cui Y.D.
 Dai B.Z.
 Dai H.L.
 Dai Z.G.
 Danzengluobu
 Della Volpe D.
 Dong X.Q.
 Duan K.K.
 Fan J.H.
 Fan Y.Z.
 Fang J.
 Fang K.
 Feng C.F.
 Feng L.
 Feng S.H.
 Feng X.T.
 Feng Y.L.
 Gabici S.
 Gao B.
 Gao C.D.
 Gao L.Q.
 Gao Q.
 Gao W.
 Gao W.K.
 Ge M.M.
 Geng L.S.
 Giacinti G.
 Gong G.H.
 Gou Q.B.
 Gu M.H.
 Guo F.L.
 Guo X.L.
 Guo Y.Q.
 Guo Y.Y.
 Han Y.A.
 He H.H.
 He H.N.
 He J.Y.
 He X.B.
 He Y.
 Heller M.
 Hor Y.K.
 Hou B.W.
 Hou C.
 Hou X.
 Hu H.B.
 Hu Q.
 Hu S.C.
 Huang D.H.
 Huang T.Q.
 Huang W.J.
 Huang X.T.
 Huang X.Y.
 Huang Y.
 Huang Z.C.
 Ji X.L.
 Jia H.Y.
 Jia K.
 Jiang K.
 Jiang X.W.
 Jiang Z.J.
 Jin M.
 Kang M.M.
 Ke T.
 Kuleshov D.
 Kurinov K.
 Li B.B.
 Li C.

Author's Affiliation

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
 Sichuan University
 National Astronomical Observatories Chinese Academy of Sciences
 Max-Planck-Institut für Kernphysik
 Southwest Jiaotong University
 Purple Mountain Observatory Chinese Academy of Sciences
 Université de Genève
 Hebei Normal University
 Tibet University
 TIANFU Cosmic Ray Research Center

Other Contributor(s)

Mahidol University

Abstract

The diffuse Galactic γ-ray emission, mainly produced via interactions between cosmic rays and the interstellar medium and/or radiation field, is a very important probe of the distribution, propagation, and interaction of cosmic rays in the Milky Way. In this Letter, we report the measurements of diffuse γ rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner (15°<l<125°, |b|<5°) and outer (125°<l<235°, |b|<5°) Galactic plane are detected with 29.1σ and 12.7σ significance, respectively. The outer Galactic plane diffuse emission is detected for the first time in the very- to ultra-high-energy domain (E>10  TeV). The energy spectrum in the inner Galaxy regions can be described by a power-law function with an index of -2.99±0.04, which is different from the curved spectrum as expected from hadronic interactions between locally measured cosmic rays and the line-of-sight integrated gas content. Furthermore, the measured flux is higher by a factor of ∼3 than the prediction. A similar spectrum with an index of -2.99±0.07 is found in the outer Galaxy region, and the absolute flux for 10≲E≲60  TeV is again higher than the prediction for hadronic cosmic ray interactions. The latitude distributions of the diffuse emission are consistent with the gas distribution, while the longitude distributions show clear deviation from the gas distribution. The LHAASO measurements imply that either additional emission sources exist or cosmic ray intensities have spatial variations.

Keyword(s)

Physics and Astronomy

Availability

URI

https://repository.li.mahidol.ac.th/handle/20.500.14594/90978

Collections

Scopus 2023