On the Potential Galactic Origin of the Ultra-High-Energy Event KM3-230213A

The KM3NeT observatory detected the most energetic neutrino candidate ever observed, with an energy between 72 PeV and 2.6 EeV at the 90 % confidence level. The observed neutrino event is likely of cosmic origin. This study investigates the possibility that the neutrino was produced within the Milky Way. Considering the low flux of the Galactic diffuse emission at these energies, the lack of a nearby potential Galactic particle accelerator aligned with the event’s direction, and the theoretical challenges of accelerating particles to such high energies in Galactic systems, we conclude that an extragalactic origin of the event is highly probable.