Astrophysicists at the University of Utah and the Telescope Array have actually identified cosmic rays with energies beyond theoretical limits, challenging existing understanding of particle physics. These discoveries, including the Oh-My-God and Amaterasu particles, point to unidentified cosmic phenomena and are the focus of continuous research.
Second only to the Oh-My-God particle, the recently dubbed Amaterasu particle deepens the mystery of the particle, propagation and origin physics of rare, ultra-high-energy cosmic rays.
In 1991, the University of Utah Flys Eye experiment found the highest-energy cosmic ray ever observed. Later dubbed the Oh-My-God particle, the cosmic rays energy surprised astrophysicists. Absolutely nothing in our galaxy had the power to produce it, and the particle had more energy than was in theory possible for cosmic rays taking a trip to Earth from other galaxies. Put simply, the particle should not exist.
Astronomical Mysteries
The Telescope Array has actually considering that observed more than 30 ultra-high-energy cosmic rays, though none approaching the Oh-My-God-level energy. No observations have yet exposed their origin or how they are able to take a trip to the Earth.
Artists illustration of the incredibly energetic cosmic ray observed by a surface detector array of the Telescope Array experiment, called “Amaterasu particle.” Credit: Osaka Metropolitan University/L-INSIGHT, Kyoto University/Ryuunosuke Takeshige
On May 27, 2021, the Telescope Array experiment spotted the second-highest extreme-energy cosmic ray. At 2.4 x 1020eV, the energy of this single subatomic particle is equivalent to dropping a brick on your toe from waist height.
” The particles are so high energy, they should not be impacted by galactic and extra-galactic magnetic fields. You must have the ability to point to where they come from in the sky,” said John Matthews, Telescope Array co-spokesperson at the U and co-author of the study. “But when it comes to the Oh-My-God particle and this new particle, you trace its trajectory to its source and theres absolutely nothing high energy enough to have actually produced it. Thats the secret of this– what the heck is going on?”
The Amaterasu Particle
In their observation, which was published on November 24, 2023, in the journal Science, a worldwide collaboration of scientists explained the ultra-high-energy cosmic ray, evaluated its attributes, and concluded that the unusual phenomena might follow particle physics unknown to science. The researchers called it the Amaterasu particle after the sun goddess in Japanese mythology. The Oh-My-God and the Amaterasu particles were identified utilizing various observation techniques, validating that while unusual, these ultra-high energy occasions are real.
Artists illustration of ultra-high-energy cosmic ray astronomy to clarify very energetic phenomena in contrast to a weaker cosmic ray that is affected by electro-magnetic fields. Credit: Osaka Metropolitan University/Kyoto University/Ryuunosuke Takeshige
” These occasions appear like theyre originating from completely various locations in the sky. Its not like theres one mystical source,” stated John Belz, professor at the U and co-author of the study. “It could be problems in the structure of spacetime, colliding cosmic strings. I indicate, Im just spit-balling insane ideas that individuals are coming up with since theres not a standard description.”
Natures Particle Accelerators
Cosmic rays are echoes of violent celestial events that have actually stripped matter to its subatomic structures and hurled it through the Universe at almost the speed of light. Essentially cosmic rays are charged particles with a large range of energies including positive protons, negative electrons, or entire atomic nuclei that take a trip through area and rain down onto Earth nearly constantly.
Cosmic rays hit Earths upper environment and blasts apart the nucleus of oxygen and nitrogen gas, generating many secondary particles. These take a trip a brief range in the atmosphere and repeat the process, constructing a shower of billions of secondary particles that spread to the surface area. The footprint of this secondary shower is huge and requires that detectors cover a location as big as the Telescope Array. The surface detectors utilize a suite of instrumentation that offers scientists information about each cosmic ray; the timing of the signal shows its trajectory and the amount of charged particles striking each detector exposes the primary particles energy.
Due to the fact that particles have a charge, their flight path resembles a ball in a pinball device as they zigzag versus the electro-magnetic fields through the cosmic microwave background. Particles with Oh-My-God and Amaterasu energy blast through intergalactic area fairly unbent.
” Things that people believe of as energetic, like supernova, are nowhere near energetic enough for this. You require big amounts of energy, actually high electromagnetic fields to restrict the particle while it gets sped up,” stated Matthews.
Mystery of Ultra-High-Energy Cosmic Rays
Ultra-high-energy cosmic rays need to exceed 5 x 1019 eV. This indicates that a single subatomic particle brings the very same kinetic energy as a significant league pitchers quick ball and has 10s of countless times more energy than any human-made particle accelerator can attain. Astrophysicists computed this theoretical limit, understood as the Greisen– Zatsepin– Kuzmin (GZK) cutoff, as the optimum energy a proton can hold taking a trip over cross countries before the impact of interactions of the microwave background radiation take their energy. Known source candidates, such as active stellar nuclei or great voids with accretion disks producing particle jets, tend to be more than 160 million light years away from Earth. The brand-new particles 2.4 x 1020 eV and the Oh-My-God particles 3.2 x 1020 eV quickly exceed the cutoff.
A much heavier particle, like iron nuclei, are heavier, have more charge and are more susceptible to bending in a magnetic field than a lighter particle made of protons from a hydrogen atom. Particle physics determines that a cosmic ray with energy beyond the GZK cutoff is too effective for the microwave background to misshape its course, however back tracing its trajectory points towards empty area.
” Maybe electromagnetic fields are more powerful than we thought, however that disagrees with other observations that reveal theyre not strong enough to produce considerable curvature at these ten-to-the-twentieth electron volt energies,” stated Belz. “Its a real secret.”
Expanding Research and the Telescope Array
The Telescope Array is distinctively positioned to identify ultra-high-energy cosmic rays. It sits at about 1,200 m (4,000 ft), the elevation sweet-spot that permits secondary particles maximum development, but before they start to decay. Its location in Utahs West Desert provides ideal climatic conditions in two methods: the dry air is important because humidity will take in the ultraviolet light required for detection; and the areas dark skies are important, as light pollution will develop too much noise and obscure the cosmic rays.
Astrophysicists are still baffled by the mystical phenomena. The Telescope Array remains in the middle of an expansion that they hope will assist break the case. When finished, 500 new scintillator detectors will expand the Telescope Array will sample cosmic ray-induced particle showers throughout 2,900 km2 (1,100 mi2 ), an area nearly the size of Rhode Island. The larger footprint will hopefully record more occasions that will shed light on whats going on.
For more on this discovery:
Later dubbed the Oh-My-God particle, the cosmic rays energy surprised astrophysicists. “But in the case of the Oh-My-God particle and this brand-new particle, you trace its trajectory to its source and theres nothing high energy enough to have produced it. The surface area detectors use a suite of instrumentation that offers scientists info about each cosmic ray; the timing of the signal reveals its trajectory and the amount of charged particles striking each detector reveals the main particles energy.
The brand-new particles 2.4 x 1020 eV and the Oh-My-God particles 3.2 x 1020 eV quickly surpass the cutoff.
A much heavier particle, like iron nuclei, are heavier, have more charge and are more vulnerable to bending in a magnetic field than a lighter particle made of protons from a hydrogen atom.
Recommendation: “An exceptionally energetic cosmic ray observed by a surface detector variety” 23 November 2023, Science.DOI: 10.1126/ science.abo5095.
