Scientists investigate the source of the ‘sun goddess’ particle

Scientists are investigating the origin of Amaterasu, one of the most energetic particles ever detected from space. The particle, named after the Japanese sun goddess, was first observed in 2021 and carries an energy level 40 million times greater than that achieved by the Large Hadron Collider.

Amaterasu is a cosmic ray, a type of energetic charged particle traveling through space at nearly the speed of light. It is the second most energetic cosmic ray ever detected, following the “Oh-My-God” particle identified in 1991. The rarity of such high-energy particles makes understanding their origins a priority for researchers, with current theories suggesting they originate from supernova explosions and the central regions of galaxies with supermassive black holes.

The Local Void Anomaly

The puzzle surrounding Amaterasu is that it appears to have originated from the Local Void, a region of space largely devoid of galaxies and the extreme environments typically associated with the production of high-energy cosmic rays.

A Nearby Origin

Researchers Francesca Capel and Nadine Bourriche at the Max Planck Institute for Physics have proposed that Amaterasu may not have originated within the Local Void. Their analysis suggests the particle could have been produced in a nearby star-forming galaxy, such as M82.

The researchers utilized a novel data-driven approach to trace Amaterasu’s possible path through the cosmos, considering the influence of magnetic fields. They employed a statistical technique called Approximate Bayesian Computation to compare simulations with observational data and infer probable source locations.

Implications for Cosmic Ray Research

The analysis produced probability maps indicating potential origin points for Amaterasu beyond the Local Void. This research has broader implications, potentially aiding in the identification of cosmic events that act as high-energy cosmic ray factories.

Understanding ultra-high-energy cosmic rays can provide insights into how the Universe accelerates matter to such extreme energies and how matter behaves under those conditions. The team’s findings were published in The Astrophysical Journal.