Scientists at Osaka Metropolitan University have identified a remarkably energetic cosmic particle. The name chosen for this extraordinary signal honors a Sun Goddess, Amaterasu, reflecting the powerful nature of the detection. The finding appears in the scientific record as part of ongoing research in high-energy astrophysics.
Cosmic rays are fast-moving charged particles arriving from outer space. Some of these rare beams reach energies measured in exa-electronvolts, or EeV, which is nearly a million times higher than the most potent man-made accelerators. A global team of researchers has pursued these elusive particles through a long-running effort known as the Telescope Array experiment, established in 2008. The apparatus comprises 507 sensor stations spread over a wide area to capture fleeting signals from space.
On May 27, 2021, within the Telescope Array program, scientists reported the detection of the Amaterasu particle with an energy around 244 EeV. Observations pointed to a vast underdensity, or void, in the universe along the path from which the particle arrived. The record also notes the existence of the highest-energy cosmic ray ever observed, the so-called Oh My God particle, first identified in 1991 with an energy of about 320 EeV.
Researchers note that the direction of these arriving cosmic rays did not align with any clearly identifiable astronomical object. This absence raises the possibility that unknown energetic events or sources beyond current catalogs may contribute to these extreme signals.
As scientists continue to map the high-energy sky, questions persist about how such particles are produced, how they travel through intergalactic space, and what they reveal about the most energetic processes in the cosmos. Ongoing observations aim to uncover whether unseen phenomena govern these extraordinary arrivals and what they imply for our understanding of the universe’s most violent environments.
In the study of cosmic evolution, the role of dwarf galaxies has long intrigued astronomers, particularly regarding star formation patterns. These small galaxies sometimes harbor intense periods of stellar birth, offering clues about the mechanisms that regulate star formation across different galactic environments.