(Source-Space.com)
In 1991, astrophysicists at the University of Utah Fly’s Eye experiment stumbled upon an anomaly that defied the laws of cosmic physics – an ultra-high-energy cosmic ray later dubbed the Oh-My-God particle. Its energy levels surpassed anything ever observed, leaving scientists baffled as nothing within our galaxy could account for its existence. Fast forward to 2021, and the mystery deepens as the Telescope Array, led by the University of Utah and the University of Tokyo, detected the second-highest extreme-energy cosmic ray, named the Amaterasu particle. Published on Nov. 23, 2023, in the journal Science, the findings indicate that these rare phenomena might be governed by particle physics yet unknown to science.
Not affected by galactic and extra-galactic magnetic fields
The Telescope Array, a collaborative effort involving 507 surface detector stations covering 700 km2 outside Delta, Utah, observed the Amaterasu particle on May 27, 2021. With an energy level of 2.4 x 1020eV, equivalent to the force of dropping a brick on your toe from waist height, this enigmatic particle triggered 23 detectors in the northwest region of the array, spanning an area of 48 km2. Its trajectory seemingly originated from the Local Void, an emptiness in space bordering the Milky Way galaxy.
John Matthews, co-spokesperson at the U and study co-author, expressed the perplexity of these observations. “The particles are so high energy, they shouldn’t be affected by galactic and extra-galactic magnetic fields. You should be able to point to where they come from in the sky,” he explained. “But in the case of the Oh-My-God particle and this new particle, you trace its trajectory to its source and there’s nothing high energy enough to have produced it. That’s the mystery of this—what the heck is going on?”
The international collaboration of researchers detailed their observations, characteristics, and conclusions in the Science journal, suggesting that the Amaterasu particle could be indicative of particle physics yet to be unraveled. The peculiarities of these ultra-high-energy cosmic rays challenge conventional explanations, leading to speculation about potential sources such as defects in spacetime structure or colliding cosmic strings.
Existence of ultra-high-energy events
John Belz, a professor at the U and co-author of the study, noted, “These events seem like they’re coming from completely different places in the sky. It’s not like there’s one mysterious source. It could be defects in the structure of spacetime, colliding cosmic strings. I mean, I’m just spit-balling crazy ideas that people are coming up with because there’s not a conventional explanation.”
The discovery of the Amaterasu particle and the enigmatic Oh-My-God particle before it underscores the existence of ultra-high-energy events that defy our current understanding of cosmic phenomena. As researchers delve into the intricacies of these natural particle accelerators, the cosmos continues to offer mysteries that challenge the limits of our scientific comprehension.
