Ultrahigh-energy cosmic rays may be ultraheavy nuclei
Updated
Updated · BIOENGINEER.ORG · May 7
Ultrahigh-energy cosmic rays may be ultraheavy nuclei
14 articles · Updated · BIOENGINEER.ORG · May 7
A Penn State-led study says particles like the Amaterasu event detected in Utah in 2021 could retain extreme energies better than protons or light nuclei.
Simulations found nuclei heavier than iron lose less energy across intergalactic space and follow different magnetic deflections, potentially explaining why some rays appear to arrive from cosmic voids.
The findings broaden likely sources to magnetars, black hole-forming stellar deaths and neutron star mergers, and could guide future tests by AugerPrime in Argentina and other next-generation observatories.
Are invisible star mergers, not empty voids, the true source of the mysterious Amaterasu particle?
Could these ultraheavy cosmic rays help us finally detect the ghostly neutrino leftovers from the Big Bang?
With conflicting data from observatories, are the universe's most powerful particles light, heavy, or a perplexing mix of both?
The Amaterasu Particle and the Role of Ultraheavy Nuclei in Cosmic Ray Origins
Overview
In May 2021, the Telescope Array detected the Amaterasu particle, an ultra-high-energy cosmic ray with energy of 224 EeV, initially puzzling scientists because its arrival pointed toward the empty Local Void. Researchers modeled its journey assuming it was an iron nucleus, using advanced simulations that revealed a wider possible source region beyond the void. Ultraheavy nuclei like iron survive long cosmic travels better than protons due to slower energy loss via photodisintegration, allowing them to reach Earth from distant accelerators such as collapsars and neutron star mergers. These heavy nuclei experience strong magnetic deflections, complicating source identification, but ongoing upgrades and future observatories aim to improve composition measurements and trace these particles back to their cosmic origins.