Earth-Directed Blazar Jets May Explain Record Ultra-High-Energy Neutrino
A 220 PeV neutrino detected by KM3NeT in 2023 is examined for origins; a population of blazars—jets from active galactic nuclei aimed at Earth—could account for such events without exceeding the extragalactic gamma-ray background measured by Fermi, though no electromagnetic counterpart was found and IceCube’s non-detection constrains the scenario. The study shows the blazar-population model is plausible within a defined parameter range and highlights the need for future KM3NeT upgrades and more data to confirm or refute this diffuse-origin explanation.