Detection of emission from Cygnus Cocoon above 100TeV with LHAASO
1
Issued Date
2022-03-18
Resource Type
eISSN
18248039
Scopus ID
2-s2.0-85145778198
Journal Title
Proceedings of Science
Volume
395
Rights Holder(s)
SCOPUS
Bibliographic Citation
Proceedings of Science Vol.395 (2022)
Suggested Citation
Li C. Detection of emission from Cygnus Cocoon above 100TeV with LHAASO. Proceedings of Science Vol.395 (2022). Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/86548
Title
Detection of emission from Cygnus Cocoon above 100TeV with LHAASO
Author(s)
Author's Affiliation
State Key Laboratory of Particle Detection & Electronics
Nanjing University
Shanghai Astronomical Observatory Chinese Academy of Sciences
Institute for Nuclear Research of the Russian Academy of Sciences
Shandong University
Wuhan University
Yunnan University
Institute of High Energy Physics Chinese Academy of Science
University of Chinese Academy of Sciences
Guangzhou University
Tsinghua University
Sun Yat-Sen University
University of Science and Technology of China
Zhengzhou University
Institiúid Ard-Lénn Bhaile Átha Cliath
Università degli Studi di Napoli Federico II
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
Nanjing University
Shanghai Astronomical Observatory Chinese Academy of Sciences
Institute for Nuclear Research of the Russian Academy of Sciences
Shandong University
Wuhan University
Yunnan University
Institute of High Energy Physics Chinese Academy of Science
University of Chinese Academy of Sciences
Guangzhou University
Tsinghua University
Sun Yat-Sen University
University of Science and Technology of China
Zhengzhou University
Institiúid Ard-Lénn Bhaile Átha Cliath
Università degli Studi di Napoli Federico II
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)
Abstract
The origin of PeV cosmic rays in the Galaxy is a long-standing puzzle. Superbubble or massive star cluster (MSC) has been suggested as powerful cosmic-ray accelerators. Cygnus Cocoon, an extended gamma-ray source, is likely associated with the MSC Cygnus OB2. Previous observations have shown that its spectrum extends up to 100 TeV with a break around 10 TeV. The spatial coincidence between the gamma-ray emission and molecular clouds in the region implies the hadronic origin of the gamma-ray emission, supporting Cygnus cocoon as a cosmic-ray proton accelerator. However, lack of a precise measurement of the spectrum beyond 100 TeV as well as relevant morphology prevent people from concluding that it is the source of PeV cosmic rays. We here report the observation of LHAASO-KM2A on this region. The maximum significance above 25 TeV is about 21.8σ. A photo with energy up to 1.4 PeV is detected from this region, which indicates the spectrum can extend up to 1 PeV. Such a result may be considered as the evidence for cosmic ray accelerated beyond PeV in Cygnus Cocoon.