Cascaded Gamma-ray Emission Associated with the KM3NeT Ultra-High-Energy Event KM3-230213A

Fuente: arXiv
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Main Authors: Fang, Ke, Halzen, Francis, Hooper, Dan
Format: Preprint
Published: 2025
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author Fang, Ke
Halzen, Francis
Hooper, Dan
author_facet Fang, Ke
Halzen, Francis
Hooper, Dan
contents A neutrino-like event with an energy of $\sim 220 \,{\rm PeV}$ was recently detected by the KM3NeT/ARCA telescope. If this neutrino comes from an astrophysical source, or from the interaction of an ultra-high-energy cosmic ray in the intergalactic medium, the ultra-high-energy gamma rays that are co-produced with the neutrinos will scatter with the extragalactic background light, producing an electromagnetic cascade and resulting in emission at GeV-to-TeV energies. In this paper, we compute the gamma-ray flux from this neutrino source considering various source distances and strengths of the intergalactic magnetic field (IGMF). We find that the associated gamma-ray emission could be observed by existing imaging air cherenkov telescopes and air shower gamma-ray observatories, unless the strength of the IGMF is $B\gtrsim 3\times 10^{-13}$ G, or the ultra-high-energy gamma-rays are attenuated inside of the source itself. In the latter case, this source is expected to be radio-loud.
format Preprint
id arxiv_https___arxiv_org_abs_2502_09545
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Cascaded Gamma-ray Emission Associated with the KM3NeT Ultra-High-Energy Event KM3-230213A
Fang, Ke
Halzen, Francis
Hooper, Dan
High Energy Astrophysical Phenomena
A neutrino-like event with an energy of $\sim 220 \,{\rm PeV}$ was recently detected by the KM3NeT/ARCA telescope. If this neutrino comes from an astrophysical source, or from the interaction of an ultra-high-energy cosmic ray in the intergalactic medium, the ultra-high-energy gamma rays that are co-produced with the neutrinos will scatter with the extragalactic background light, producing an electromagnetic cascade and resulting in emission at GeV-to-TeV energies. In this paper, we compute the gamma-ray flux from this neutrino source considering various source distances and strengths of the intergalactic magnetic field (IGMF). We find that the associated gamma-ray emission could be observed by existing imaging air cherenkov telescopes and air shower gamma-ray observatories, unless the strength of the IGMF is $B\gtrsim 3\times 10^{-13}$ G, or the ultra-high-energy gamma-rays are attenuated inside of the source itself. In the latter case, this source is expected to be radio-loud.
title Cascaded Gamma-ray Emission Associated with the KM3NeT Ultra-High-Energy Event KM3-230213A
topic High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2502.09545