Detection of a new GeV source in the outer region of the Coma cluster: a signature of external accretion shock ?
Fuente:
arXiv
Gespeichert in:
| Hauptverfasser: | , , , , , , |
|---|---|
| Format: | Preprint |
| Veröffentlicht: |
2024
|
| Schlagworte: | |
| Online-Zugang: | |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| _version_ | 1866910773283913728 |
|---|---|
| author | Chen, Xiao-Bin Wang, Kai Huang, Yi-Yun Zhang, Hai-Ming Xi, Shao-Qiang Liu, Ruo-Yu Wang, Xiang-Yu |
| author_facet | Chen, Xiao-Bin Wang, Kai Huang, Yi-Yun Zhang, Hai-Ming Xi, Shao-Qiang Liu, Ruo-Yu Wang, Xiang-Yu |
| contents | The supersonic flow motions associated with infall of baryonic gas toward sheets and filaments, as well as cluster mergers, produces large-scale shock waves. The shocks associated with galaxy clusters can be classified mainly into two categories: internal shocks appear in the hot intracluster medium within the viral radius, and external accretion shocks form in the outer cold region well outside of the virial radius. Cosmic-ray (CR) electrons and/or protons accelerated by these shocks are expected to produce gamma-rays through inverse-Compton scatterings (ICS) or inelastic $pp$ collisions respectively. Recent studies have found a spatially extended GeV source within the virial radius, consistent with the internal shock origin. Here we report the detection of a new GeV source at a distance of about 2.8$^\circ$ from the center of the Coma cluster through the analysis of 16.2 years of Fermi-LAT data. The hard spectrum of the source, in agreement with the ICS origin, and its location in a large-scale filament of galaxies points to the external accretion shock origin. The gamma-ray ($0.1-10^3$ GeV) luminosity of the source, $1.4\times 10^{42}~ {\rm erg~s^{-1}}$, suggests that a fraction $\sim 10^{-3}$ of the kinetic energy flux through the shock-surface is transferred to relativistic CR electrons. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2412_02436 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Detection of a new GeV source in the outer region of the Coma cluster: a signature of external accretion shock ? Chen, Xiao-Bin Wang, Kai Huang, Yi-Yun Zhang, Hai-Ming Xi, Shao-Qiang Liu, Ruo-Yu Wang, Xiang-Yu High Energy Astrophysical Phenomena The supersonic flow motions associated with infall of baryonic gas toward sheets and filaments, as well as cluster mergers, produces large-scale shock waves. The shocks associated with galaxy clusters can be classified mainly into two categories: internal shocks appear in the hot intracluster medium within the viral radius, and external accretion shocks form in the outer cold region well outside of the virial radius. Cosmic-ray (CR) electrons and/or protons accelerated by these shocks are expected to produce gamma-rays through inverse-Compton scatterings (ICS) or inelastic $pp$ collisions respectively. Recent studies have found a spatially extended GeV source within the virial radius, consistent with the internal shock origin. Here we report the detection of a new GeV source at a distance of about 2.8$^\circ$ from the center of the Coma cluster through the analysis of 16.2 years of Fermi-LAT data. The hard spectrum of the source, in agreement with the ICS origin, and its location in a large-scale filament of galaxies points to the external accretion shock origin. The gamma-ray ($0.1-10^3$ GeV) luminosity of the source, $1.4\times 10^{42}~ {\rm erg~s^{-1}}$, suggests that a fraction $\sim 10^{-3}$ of the kinetic energy flux through the shock-surface is transferred to relativistic CR electrons. |
| title | Detection of a new GeV source in the outer region of the Coma cluster: a signature of external accretion shock ? |
| topic | High Energy Astrophysical Phenomena |
| url | https://arxiv.org/abs/2412.02436 |