The Astrophysical Journal (Jan 2023)

Observation of Gamma Rays up to 320 TeV from the Middle-aged TeV Pulsar Wind Nebula HESS J1849−000

  • M. Amenomori,
  • S. Asano,
  • Y. W. Bao,
  • X. J. Bi,
  • D. Chen,
  • T. L. Chen,
  • W. Y. Chen,
  • Xu Chen,
  • Y. Chen,
  • Cirennima,
  • S. W. Cui,
  • Danzengluobu,
  • L. K. Ding,
  • J. H. Fang,
  • K. Fang,
  • C. F. Feng,
  • Zhaoyang Feng,
  • Z. Y. Feng,
  • Qi Gao,
  • A. Gomi,
  • Q. B. Gou,
  • Y. Q. Guo,
  • Y. Y. Guo,
  • Y. Hayashi,
  • H. H. He,
  • Z. T. He,
  • K. Hibino,
  • N. Hotta,
  • Haibing Hu,
  • H. B. Hu,
  • K. Y. Hu,
  • J. Huang,
  • H. Y. Jia,
  • L. Jiang,
  • P. Jiang,
  • H. B. Jin,
  • K. Kasahara,
  • Y. Katayose,
  • C. Kato,
  • S. Kato,
  • I. Kawahara,
  • T. Kawashima,
  • K. Kawata,
  • M. Kozai,
  • D. Kurashige,
  • Labaciren,
  • G. M. Le,
  • A. F. Li,
  • H. J. Li,
  • W. J. Li,
  • Y. Li,
  • Y. H. Lin,
  • B. Liu,
  • C. Liu,
  • J. S. Liu,
  • L. Y. Liu,
  • M. Y. Liu,
  • W. Liu,
  • H. Lu,
  • X. R. Meng,
  • Y. Meng,
  • K. Munakata,
  • K. Nagaya,
  • Y. Nakamura,
  • Y. Nakazawa,
  • H. Nanjo,
  • C. C. Ning,
  • M. Nishizawa,
  • R. Noguchi,
  • M. Ohnishi,
  • S. Okukawa,
  • S. Ozawa,
  • X. Qian,
  • X. L. Qian,
  • X. B. Qu,
  • T. Saito,
  • Y. Sakakibara,
  • M. Sakata,
  • T. Sako,
  • T. K. Sako,
  • T. Sasaki,
  • J. Shao,
  • M. Shibata,
  • A. Shiomi,
  • H. Sugimoto,
  • W. Takano,
  • M. Takita,
  • Y. H. Tan,
  • N. Tateyama,
  • S. Torii,
  • H. Tsuchiya,
  • S. Udo,
  • H. Wang,
  • S. F. Wang,
  • Y. P. Wang,
  • Wangdui,
  • H. R. Wu,
  • Q. Wu,
  • J. L. Xu,
  • L. Xue,
  • Z. Yang,
  • Y. Q. Yao,
  • J. Yin,
  • Y. Yokoe,
  • Y. L. Yu,
  • A. F. Yuan,
  • L. M. Zhai,
  • H. M. Zhang,
  • J. L. Zhang,
  • X. Zhang,
  • X. Y. Zhang,
  • Y. Zhang,
  • Yi Zhang,
  • Ying Zhang,
  • S. P. Zhao,
  • Zhaxisangzhu,
  • X. X. Zhou,
  • Y. H. Zou

DOI
https://doi.org/10.3847/1538-4357/acebce
Journal volume & issue
Vol. 954, no. 2
p. 200

Abstract

Read online

Gamma rays from HESS J1849−000, a middle-aged TeV pulsar wind nebula (PWN), are observed by the Tibet air shower array and the muon detector array. The detection significance of gamma rays reaches 4.0 σ and 4.4 σ levels above 25 TeV and 100 TeV, respectively, in units of the Gaussian standard deviation σ . The energy spectrum measured between 40 TeV < E < 320 TeV for the first time is described with a simple power-law function of ${dN}/{dE}={(2.86\pm 1.44)\times {10}^{-16}(E/40\,\mathrm{TeV})}^{-2.24\pm 0.41}\,{\mathrm{TeV}}^{-1}\,{\mathrm{cm}}^{-2}\,{{\rm{s}}}^{-1}$ . The gamma-ray energy spectrum from the sub-TeV ( E < 1 TeV) to sub-PeV (100 TeV < E < 1 PeV) ranges, including the results of previous studies, can be modeled with the leptonic scenario, i.e., inverse Compton scattering by high-energy electrons accelerated by the PWN of PSR J1849−0001. On the other hand, the gamma-ray energy spectrum can also be modeled with the hadronic scenario in which gamma rays are generated from the decay of neutral pions produced by collisions between accelerated cosmic-ray protons and the ambient molecular cloud found in the gamma-ray-emitting region. The cutoff energy of cosmic-ray protons E _p,cut is estimated as ${\mathrm{log}}_{10}({E}_{{\rm{p}},\mathrm{cut}}/\mathrm{TeV})={3.73}_{-0.66}^{+2.98}$ , suggesting that protons are accelerated up to the PeV energy range. Our study thus proposes that HESS J1849−000 should be further investigated as a new candidate as a Galactic PeV cosmic-ray accelerator, or “PeVatron.”

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