Scientists have identified an extraordinary and exceptionally high-energy particle that makes its way to Earth and causes bafflement due to its origin from a seemingly empty region of space.
This particle, called ‘Amaterasu’ in Japanese folklore after the sun goddess, is among the most energetic cosmic rays ever observed.
Traditionally, it was believed that only colossal cosmic phenomena, which exceed the magnitude of a star’s explosion, were capable of generating such intense particles. Yet the rise of Amaterasu appears to be linked to the Local Void, a desolate swath bordering the Milky Way Galaxy.
“You trace its trajectory back to the source and there is nothing with enough energy to have produced it,” says Prof. John Matthews of the University of Utah and co-author of the paper in the journal Science describing the discovery. “That’s the mystery of this – what the hell is going on?”
The Amaterasu particle has an energy of more than 240 exa-electron volts (EeV), millions of times more than the particles produced in the Large Hadron Collider, the most powerful accelerator ever built, and equal to the energy of a golf ball traveling at a speed of moving at 150 km/h. It is only second to the Oh-My-God particle, another ultra-high energy cosmic ray that came in at 320 EeV and was detected in 1991.
“Things that people consider energetic, like a supernova, are not nearly energetic enough for this,” says Matthews. “You need enormous amounts of energy, really high magnetic fields, to trap the particle as it is accelerated.”
Toshihiro Fujii, associate professor at Osaka Metropolitan University in Japan, said: “When I first discovered this ultra-high energy cosmic ray, I thought there must have been a mistake as it showed an energy level unprecedented in recent memory. thirty years. .”
“It seems like these events are coming from completely different places in the sky. It is not that there is one mysterious source,” says Prof. John Belz of the University of Utah and co-author of the article.
“It could be defects in the structure of spacetime, clashing cosmic strings. I mean, I just spit out crazy ideas that people come up with because there’s no conventional explanation.
Extremely high-energy cosmic rays come from outside the Milky Way, but their exact sources are unknown.
Most scientists think they are accelerated in violent cosmic environments, such as the jets of radiation that shoot out of the regions around certain supermassive black holes, or starburst galaxies that form stars at a frantic pace.
Whatever their origin, the particles must come from the relatively nearby cosmic environment.
