Guardado en:
Detalles Bibliográficos
Autores principales: Xue, Rui, He, Jia-Chun, Xiong, Dingrong, Wang, Ze-Rui
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:https://arxiv.org/abs/2508.01986
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866916879089532928
author Xue, Rui
He, Jia-Chun
Xiong, Dingrong
Wang, Ze-Rui
author_facet Xue, Rui
He, Jia-Chun
Xiong, Dingrong
Wang, Ze-Rui
contents Recent LHAASO observations hint at potential spectral hardening around 20 TeV in M87's very high energy (VHE) emission, suggesting a possible new radiation component. In this work, we construct averaged multiwavelength SEDs by combining data from Chandra and Swift-UVOT/XRT covering the same period as the LHAASO detection to investigate the origin of this feature. We test several radiation mechanisms, including the pp interaction, proton synchrotron emission, photomeson process and two-zone leptonic model. We find that only the pion decay gamma rays in pp interactions can interpret this feature in the framework of the one-zone model. With analytical analysis, we prove that proton synchrotron emission cannot generate a hard spectrum above 0.17~TeV. For photomeson model, it requires an emission zone compressed near the Schwarzschild radius of the central supermassive black hole, incompatible with broadband optical-GeV spectral constraints. In addition, the two-zone leptonic model also emerges as a viable alternative.
format Preprint
id arxiv_https___arxiv_org_abs_2508_01986
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle On the origin of a possible hard VHE spectrum from M87 discovered by LHAASO
Xue, Rui
He, Jia-Chun
Xiong, Dingrong
Wang, Ze-Rui
High Energy Astrophysical Phenomena
Astrophysics of Galaxies
Recent LHAASO observations hint at potential spectral hardening around 20 TeV in M87's very high energy (VHE) emission, suggesting a possible new radiation component. In this work, we construct averaged multiwavelength SEDs by combining data from Chandra and Swift-UVOT/XRT covering the same period as the LHAASO detection to investigate the origin of this feature. We test several radiation mechanisms, including the pp interaction, proton synchrotron emission, photomeson process and two-zone leptonic model. We find that only the pion decay gamma rays in pp interactions can interpret this feature in the framework of the one-zone model. With analytical analysis, we prove that proton synchrotron emission cannot generate a hard spectrum above 0.17~TeV. For photomeson model, it requires an emission zone compressed near the Schwarzschild radius of the central supermassive black hole, incompatible with broadband optical-GeV spectral constraints. In addition, the two-zone leptonic model also emerges as a viable alternative.
title On the origin of a possible hard VHE spectrum from M87 discovered by LHAASO
topic High Energy Astrophysical Phenomena
Astrophysics of Galaxies
url https://arxiv.org/abs/2508.01986