It says "typically, energetic neutrinos from active galactic centers are thought to originate from interactions between protons and photons, producing gamma rays of comparable intensity." and suggests other theorized sources.
Another good source on this new branch of astronomy:
This article has some ideas on such an energy:
https://phys.org/news/2025-05-physicists-route-neutrinos.htm...
It says "typically, energetic neutrinos from active galactic centers are thought to originate from interactions between protons and photons, producing gamma rays of comparable intensity." and suggests other theorized sources.
Another good source on this new branch of astronomy:
https://arxiv.org/html/1501.07798v1
Newer idea (May 2026): blazars
https://www.sciencedaily.com/releases/2026/05/260523103912.h...