Cosmic ray Amaterasu's origin traced to nearby star-forming galaxies
Researchers report new evidence about the possible origin of a super-energetic cosmic particle called Amaterasu—and it's not as far away as you'd think.
Using clever simulations and comparisons with observational data, the team found that Amaterasu may have originated in relatively nearby star-forming galaxies, bringing scientists a step closer to identifying its source.
Amaterasu's journey to Earth
Amaterasu packs an insane amount of energy—roughly like dropping a brick from waist height, but all packed into one tiny particle zooming through space.
It was picked up by 23 detectors within the Telescope Array's roughly 700-square-kilometer observatory, helping scientists get closer to understanding how these ultra-high-energy cosmic rays are born.
Simulations reveal potential origins
By running simulations through the Milky Way's magnetic fields and matching models with real data, researchers suggested the origin is less likely to be empty regions of space (such as the Local Void) and pointed to nearby star-forming galaxies, notably M82, as possible sources.
Implications for understanding cosmic rays
This new method for tracing cosmic rays could help unlock how extreme environments—like exploding stars—create these wild particles.
It also pushes science closer to identifying the environments and mechanisms that can accelerate matter to ultra-high energies.