A Discussion on the Origin of the Sub-PeV Galactic Gamma-Ray Emission
Galactic diffuse gamma-ray flux measured by the Tibet AS γ experiment and the total Galactic gamma-ray flux measured by the Large High Altitude Air Shower Observatory (LHAASO) are found to be consistent, within the statistical and systematic uncertainties, for the inner Galactic plane region in the...
Saved in:
| Main Authors: | , , , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
|
| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/adcb45 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850195517727834112 |
|---|---|
| author | S. Kato R. Alves Batista M. Anzorena K. Awai D. Chen K. Fujita R. Garcia J. Huang G. Imaizumi T. Kawashima K. Kawata A. Mizuno M. Ohnishi C. Prévotat T. Sako T. K. Sako F. Sugimoto M. Takita Y. Yokoe |
| author_facet | S. Kato R. Alves Batista M. Anzorena K. Awai D. Chen K. Fujita R. Garcia J. Huang G. Imaizumi T. Kawashima K. Kawata A. Mizuno M. Ohnishi C. Prévotat T. Sako T. K. Sako F. Sugimoto M. Takita Y. Yokoe |
| author_sort | S. Kato |
| collection | DOAJ |
| description | Galactic diffuse gamma-ray flux measured by the Tibet AS γ experiment and the total Galactic gamma-ray flux measured by the Large High Altitude Air Shower Observatory (LHAASO) are found to be consistent, within the statistical and systematic uncertainties, for the inner Galactic plane region in the sub-PeV energy range ( E > 10 ^14 eV). The result suggests that the sub-PeV Galactic gamma-ray flux is dominated by the diffuse emission. On the other hand, the LHAASO observations suggest that the sub-PeV gamma-ray sources presented in the first LHAASO catalog possibly give a significant contribution to the total sub-PeV Galactic gamma-ray emission (≈60%). However, the estimate must be regarded as a conservative upper limit in the sub-PeV energy range. In fact, current gamma-ray observations imply that many of the sub-PeV gamma-ray sources detected by LHAASO have a cutoff or significant softening in their energy spectra in the several tens of TeV energy range, and the resolved-source contribution to the total sub-PeV Galactic gamma-ray emission should be much lower than the above estimate. More sophisticated discussion about the origin of the sub-PeV Galactic gamma-ray emission requires detailed spectral studies of the individual gamma-ray sources and an accurate estimate of the contamination of the source fluxes from the diffuse emission. |
| format | Article |
| id | doaj-art-83b4f1cdd43a472fa4f01475ee110c4b |
| institution | OA Journals |
| issn | 1538-4357 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj-art-83b4f1cdd43a472fa4f01475ee110c4b2025-08-20T02:13:44ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-0198429810.3847/1538-4357/adcb45A Discussion on the Origin of the Sub-PeV Galactic Gamma-Ray EmissionS. Kato0https://orcid.org/0000-0003-1043-2803R. Alves Batista1https://orcid.org/0000-0003-2656-064XM. Anzorena2K. Awai3D. Chen4K. Fujita5R. Garcia6J. Huang7G. Imaizumi8T. Kawashima9K. Kawata10https://orcid.org/0000-0001-6332-2005A. Mizuno11https://orcid.org/0009-0001-2494-4992M. Ohnishi12C. Prévotat13T. Sako14https://orcid.org/0000-0002-2589-8561T. K. Sako15https://orcid.org/0000-0002-7003-6493F. Sugimoto16M. Takita17Y. Yokoe18Institut d’Astrophysique de Paris, CNRS UMR 7095, Sorbonne Université, 98 bis bd Arago 75014, Paris, France ; sei.kato@iap.frInstitut d’Astrophysique de Paris, CNRS UMR 7095, Sorbonne Université, 98 bis bd Arago 75014, Paris, France ; sei.kato@iap.frInstitute for Cosmic Ray Research, University of Tokyo , Kashiwa 277-8582, JapanInstitute for Cosmic Ray Research, University of Tokyo , Kashiwa 277-8582, JapanNational Astronomical Observatories, Chinese Academy of Sciences , Beijing 100012, People’s Republic of ChinaInstitute for Cosmic Ray Research, University of Tokyo , Kashiwa 277-8582, JapanInstitute for Cosmic Ray Research, University of Tokyo , Kashiwa 277-8582, JapanKey Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences , Beijing 100049, People’s Republic of ChinaInstitute for Cosmic Ray Research, University of Tokyo , Kashiwa 277-8582, JapanInstitute for Cosmic Ray Research, University of Tokyo , Kashiwa 277-8582, JapanInstitute for Cosmic Ray Research, University of Tokyo , Kashiwa 277-8582, JapanInstitute for Cosmic Ray Research, University of Tokyo , Kashiwa 277-8582, JapanInstitute for Cosmic Ray Research, University of Tokyo , Kashiwa 277-8582, JapanInstitut d’Astrophysique de Paris, CNRS UMR 7095, Sorbonne Université, 98 bis bd Arago 75014, Paris, France ; sei.kato@iap.frInstitute for Cosmic Ray Research, University of Tokyo , Kashiwa 277-8582, JapanNagano Prefectural Institute of Technology , Ueda 386-1211, JapanInstitute for Cosmic Ray Research, University of Tokyo , Kashiwa 277-8582, JapanInstitute for Cosmic Ray Research, University of Tokyo , Kashiwa 277-8582, JapanInstitute for Cosmic Ray Research, University of Tokyo , Kashiwa 277-8582, JapanGalactic diffuse gamma-ray flux measured by the Tibet AS γ experiment and the total Galactic gamma-ray flux measured by the Large High Altitude Air Shower Observatory (LHAASO) are found to be consistent, within the statistical and systematic uncertainties, for the inner Galactic plane region in the sub-PeV energy range ( E > 10 ^14 eV). The result suggests that the sub-PeV Galactic gamma-ray flux is dominated by the diffuse emission. On the other hand, the LHAASO observations suggest that the sub-PeV gamma-ray sources presented in the first LHAASO catalog possibly give a significant contribution to the total sub-PeV Galactic gamma-ray emission (≈60%). However, the estimate must be regarded as a conservative upper limit in the sub-PeV energy range. In fact, current gamma-ray observations imply that many of the sub-PeV gamma-ray sources detected by LHAASO have a cutoff or significant softening in their energy spectra in the several tens of TeV energy range, and the resolved-source contribution to the total sub-PeV Galactic gamma-ray emission should be much lower than the above estimate. More sophisticated discussion about the origin of the sub-PeV Galactic gamma-ray emission requires detailed spectral studies of the individual gamma-ray sources and an accurate estimate of the contamination of the source fluxes from the diffuse emission.https://doi.org/10.3847/1538-4357/adcb45High-energy cosmic radiationGalactic cosmic raysGamma-ray astronomy |
| spellingShingle | S. Kato R. Alves Batista M. Anzorena K. Awai D. Chen K. Fujita R. Garcia J. Huang G. Imaizumi T. Kawashima K. Kawata A. Mizuno M. Ohnishi C. Prévotat T. Sako T. K. Sako F. Sugimoto M. Takita Y. Yokoe A Discussion on the Origin of the Sub-PeV Galactic Gamma-Ray Emission The Astrophysical Journal High-energy cosmic radiation Galactic cosmic rays Gamma-ray astronomy |
| title | A Discussion on the Origin of the Sub-PeV Galactic Gamma-Ray Emission |
| title_full | A Discussion on the Origin of the Sub-PeV Galactic Gamma-Ray Emission |
| title_fullStr | A Discussion on the Origin of the Sub-PeV Galactic Gamma-Ray Emission |
| title_full_unstemmed | A Discussion on the Origin of the Sub-PeV Galactic Gamma-Ray Emission |
| title_short | A Discussion on the Origin of the Sub-PeV Galactic Gamma-Ray Emission |
| title_sort | discussion on the origin of the sub pev galactic gamma ray emission |
| topic | High-energy cosmic radiation Galactic cosmic rays Gamma-ray astronomy |
| url | https://doi.org/10.3847/1538-4357/adcb45 |
| work_keys_str_mv | AT skato adiscussionontheoriginofthesubpevgalacticgammarayemission AT ralvesbatista adiscussionontheoriginofthesubpevgalacticgammarayemission AT manzorena adiscussionontheoriginofthesubpevgalacticgammarayemission AT kawai adiscussionontheoriginofthesubpevgalacticgammarayemission AT dchen adiscussionontheoriginofthesubpevgalacticgammarayemission AT kfujita adiscussionontheoriginofthesubpevgalacticgammarayemission AT rgarcia adiscussionontheoriginofthesubpevgalacticgammarayemission AT jhuang adiscussionontheoriginofthesubpevgalacticgammarayemission AT gimaizumi adiscussionontheoriginofthesubpevgalacticgammarayemission AT tkawashima adiscussionontheoriginofthesubpevgalacticgammarayemission AT kkawata adiscussionontheoriginofthesubpevgalacticgammarayemission AT amizuno adiscussionontheoriginofthesubpevgalacticgammarayemission AT mohnishi adiscussionontheoriginofthesubpevgalacticgammarayemission AT cprevotat adiscussionontheoriginofthesubpevgalacticgammarayemission AT tsako adiscussionontheoriginofthesubpevgalacticgammarayemission AT tksako adiscussionontheoriginofthesubpevgalacticgammarayemission AT fsugimoto adiscussionontheoriginofthesubpevgalacticgammarayemission AT mtakita adiscussionontheoriginofthesubpevgalacticgammarayemission AT yyokoe adiscussionontheoriginofthesubpevgalacticgammarayemission AT skato discussionontheoriginofthesubpevgalacticgammarayemission AT ralvesbatista discussionontheoriginofthesubpevgalacticgammarayemission AT manzorena discussionontheoriginofthesubpevgalacticgammarayemission AT kawai discussionontheoriginofthesubpevgalacticgammarayemission AT dchen discussionontheoriginofthesubpevgalacticgammarayemission AT kfujita discussionontheoriginofthesubpevgalacticgammarayemission AT rgarcia discussionontheoriginofthesubpevgalacticgammarayemission AT jhuang discussionontheoriginofthesubpevgalacticgammarayemission AT gimaizumi discussionontheoriginofthesubpevgalacticgammarayemission AT tkawashima discussionontheoriginofthesubpevgalacticgammarayemission AT kkawata discussionontheoriginofthesubpevgalacticgammarayemission AT amizuno discussionontheoriginofthesubpevgalacticgammarayemission AT mohnishi discussionontheoriginofthesubpevgalacticgammarayemission AT cprevotat discussionontheoriginofthesubpevgalacticgammarayemission AT tsako discussionontheoriginofthesubpevgalacticgammarayemission AT tksako discussionontheoriginofthesubpevgalacticgammarayemission AT fsugimoto discussionontheoriginofthesubpevgalacticgammarayemission AT mtakita discussionontheoriginofthesubpevgalacticgammarayemission AT yyokoe discussionontheoriginofthesubpevgalacticgammarayemission |