Amaterasu particle

The Amaterasu particle, named after the sun goddess in Japanese mythology, was an unexpected ultra-high-energy cosmic ray detected in 2021 and later identified in 2023,[1] using the Telescope Array Project observatory in Utah, United States. It had an energy exceeding 240 exa-electronvolts (EeV) and was inferred through the two dozen particles it sent toward ground detectors. This single particle appears to have emerged, inexplicably, from the Local Void, an empty area of space bordering the Milky Way galaxy.[2] The single subatomic particle held energy roughly equivalent to a brick dropping to the ground from waist height.[3]

According to study leader, Associate Professor Toshihiro Fujii from Osaka Metropolitan University, "No promising astronomical object matching the direction from which the cosmic ray arrived has been identified, suggesting possibilities of unknown astronomical phenomena and novel physical origins beyond the Standard Model."[4]

Previously reported extremely high-energy cosmic ray events include a 320 EeV particle in 1991[5] (Oh-My-God particle), a 213 EeV particle in 1993[6][1] and a 280 EeV particle in 2001.[7] This makes the Amaterasu particle the third most powerful cosmic ray to have been detected.

  1. ^ a b Telescope Array Collaboration; Abbasi, R. U.; Allen, M. G.; Arimura, R.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Shin, B. K.; Buckland, I. J.; Cheon, B. G.; Fujii, T.; Fujisue, K.; Fujita, K.; Fukushima, M.; Furlich, G. D. (2023-11-24). "An extremely energetic cosmic ray observed by a surface detector array". Science. 382 (6673): 903–907. arXiv:2311.14231. Bibcode:2023Sci...382..903T. doi:10.1126/science.abo5095. ISSN 0036-8075. PMID 37995237. S2CID 265381136.
  2. ^ Devlin, Hannah (2023-11-24). "'What the heck is going on?' Extremely high-energy particle detected falling to Earth". The Guardian. Archived from the original on November 24, 2023. Retrieved November 24, 2023.
  3. ^ Hunt, Katie (2023-11-23). "Scientists detect a cosmic ray that's almost as powerful as the 'Oh-My-God' particle". CNN. Retrieved 2023-12-07.
  4. ^ Yazgin, Evrim (2023-11-24). "Second OMG cosmic ray particle breaks physics again". Cosmos. Archived from the original on November 24, 2023. Retrieved November 24, 2023.
  5. ^ Conroy, Gemma (2023-11-23). "The most powerful cosmic ray since the Oh-My-God particle puzzles scientists". Nature. doi:10.1038/d41586-023-03677-0. PMID 37996738. S2CID 265403953.
  6. ^ Sasaki, N; et, al (2001). Proceedings of the 27th International Cosmic Ray Conference ICRC2001. Copernicus-Gesellschaft. p. 337.
  7. ^ Hayashida, N.; Honda, K.; Honda, M.; Imaizumi, S.; Inoue, N.; Kadota, K.; Kakimoto, F.; Kamata, K.; Kawaguchi, S.; Kawasumi, N.; Matsubara, Y.; Murakami, K.; Nagano, M.; Ohoka, H.; Takeda, M. (1994-12-26). "Observation of a Very Energetic Cosmic Ray Well Beyond the Predicted 2.7 K Cutoff in the Primary Energy Spectrum". Physical Review Letters. 73 (26): 3491–3494. Bibcode:1994PhRvL..73.3491H. doi:10.1103/PhysRevLett.73.3491. ISSN 0031-9007. PMID 10057397.