An artist’s rendition depicts the highly energetic cosmic ray named “Amaterasu particle,” detected by the Telescope Array experiment’s surface detector array. This illustration is credited to Osaka Metropolitan University/L-INSIGHT and Kyoto University’s Ryuunosuke Takeshige.
The Telescope Array experiment’s recent identification of an ultra-high energy cosmic ray presents a conundrum regarding its origin. This detection points to a cosmic void, posing significant challenges to existing cosmic ray origin theories and the understanding of high-energy physics.
Unveiling of a Remarkable Space-Borne Particle
The Telescope Array experiment team has reported the discovery of a cosmic ray with extraordinary energy. This particle, originating from outside our galaxy, boasts an incredible energy level exceeding 240 exa-electron volts (EeV). However, its source remains a mystery, as the trajectory of its arrival does not align with any recognized astronomical bodies.
The Enigma of High-Energy Cosmic Rays
Cosmic rays are subatomic particles from space, with Ultrahigh-energy cosmic rays (UHECRs) being particularly rare and powerful. These UHECRs have energies over 1 EeV, about a million times more than what is achieved by human-made particle accelerators. They are thought to stem from the universe’s most energetic events, like black holes, gamma-ray bursts, and active galactic nuclei. Yet, the physics and mechanisms driving their acceleration are not completely understood. Their rarity – less than one particle per century per square kilometer – makes their detection exceptionally unusual and requires instruments with extensive collection areas.
An artist’s depiction contrasts ultra-high-energy cosmic ray astronomy with weaker cosmic rays affected by electromagnetic fields. Credits go to Osaka Metropolitan University, Kyoto University, and Ryuunosuke Takeshige.
The Unique Find of the Telescope Array
On May 27, 2021, the Telescope Array (TA) experiment, a vast surface detector array in Utah covering 700 square kilometers, successfully identified a UHECR with an unprecedented energy of about 244 EeV.
The extraordinary energy of this particle implies it should have undergone minimal deviation by intervening magnetic fields, suggesting a more direct correlation to its source. Yet, its arrival direction does not correspond to any known source galaxy or other potential UHECR sources.
Its trajectory traces back to a cosmic void in the universe’s large-scale structure – an area sparse with galaxies. This finding could suggest a more significant magnetic deflection than current galactic magnetic field models predict, an undiscovered source in the local extragalactic area, or a gap in our understanding of high-energy particle physics.
- Earth’s Encounter with an Unknown, Extremely High-Energy Particle
- Astronomers Baffled by Mysterious Ultra-High-Energy Cosmic Ray
Reference: “An extremely energetic cosmic ray observed by a surface detector array” by the Telescope Array Collaboration*†, et al., published on 23 November 2023 in Science.
Frequently Asked Questions (FAQs) about High-Energy Cosmic Ray
What was the significant discovery made by the Telescope Array experiment?
The Telescope Array experiment detected an ultra-high energy cosmic ray, named the “Amaterasu particle,” which originated beyond our galaxy and has an energy level exceeding 240 exa-electron volts (EeV). This discovery is significant due to its high energy and the mystery surrounding its source, as it points to a cosmic void.
Why is the source of the high-energy cosmic ray a mystery?
The source of this cosmic ray is a mystery because its trajectory does not align with any known astronomical bodies or events. Its arrival direction points to a cosmic void, a region with very few galaxies, which challenges current theories and understanding of cosmic ray origins and high-energy physics.
What are Ultrahigh-energy cosmic rays (UHECRs)?
Ultrahigh-energy cosmic rays (UHECRs) are extremely rare and powerful subatomic charged particles from space. They possess energies above 1 exa-electron volt (EeV), which is about a million times higher than the energies reached by human-made particle accelerators. UHECRs are believed to originate from the most energetic phenomena in the Universe, such as black holes, gamma-ray bursts, and active galactic nuclei.
What makes detecting these high-energy cosmic rays challenging?
Detecting high-energy cosmic rays like the one discovered by the Telescope Array is challenging due to their infrequent nature – estimated to be less than one particle per century per square kilometer. This rarity requires instruments with vast collecting areas to capture such rare events.
How does the Telescope Array experiment contribute to astrophysics research?
The Telescope Array experiment, with its large-scale surface detector array in Utah, contributes significantly to astrophysics research by detecting rare and highly energetic cosmic rays. These detections provide valuable data that can challenge and refine existing theories about high-energy particle physics and cosmic ray origins, enhancing our understanding of the universe.
More about High-Energy Cosmic Ray
- Telescope Array Project Overview
- Understanding Cosmic Rays
- High-Energy Astrophysics Research
- Cosmic Void Phenomena
- Advanced Particle Accelerators