Latest news with #PeV
Yahoo
25-05-2025
- Science
- Yahoo
Scientists may have discovered the most powerful particle collider in the universe
When you buy through links on our articles, Future and its syndication partners may earn a commission. Supernovas can become some of the most powerful particle colliders in the universe — but only if they pass a whole lot of gas before they explode, new research finds. For almost a century, astronomers have detected high-energy particles streaming in from the distant universe. Known as cosmic rays, they are made primarily of protons and, occasionally, nuclei of heavier elements. Most cosmic rays are deflected by Earth's magnetic field or are absorbed in the upper atmosphere, but some make it all the way to the surface. Roughly once every second, a cosmic ray manages to strike your body. The cosmic rays span a broad range of energies, with the most powerful ones topping one peta-electron volt (PeV). That's one quadrillion electron volts, or up to a thousand times more powerful than the collision energies of the Large Hadron Collider, the world's most powerful atom smasher. Astronomers have long suspected that the explosive deaths of massive stars may be responsible for these extremely powerful cosmic rays. After all, these supernovas have all the right ingredients: There is a detonation with more than enough energy, a flood of elementary particles, and magnetic fields that can drive those particles into a frenzy before releasing them into the cosmos. But observations of nearby supernova remnants such as Tycho and Cassiopeia A have not met expectations; the cosmic rays coming from those places are far weaker than expected. In a paper accepted for publication in the journal Astronomy & Astrophysics, researchers have rescued the supernova hypothesis and found that, in special cases, supernova remnants are indeed capable of becoming "PeVatrons" — that is, explosions capable of generating PeV cosmic rays. Related: World's largest atom smasher turned lead into gold — and then destroyed it in an instant The team found that, before going supernova, a star must lose a significant amount of mass — at least two suns' worth of material. This is fairly common, as powerful winds can drive off the outer layers of a star's atmosphere prior to the main explosion. But crucially, that material can't disperse too widely. It has to stay dense, compact and close to the star. Then, when the supernova finally happens, the shock wave from the exploding star slams into this shell of material. And then all hell breaks loose. RELATED STORIES —Astronomers spy puzzlingly 'perfect' cosmic orb with unknown size and location —Physicists create 'black hole bomb' for first time on Earth, validating decades-old theory —Gamma-ray bursts reveal largest structure in the universe is bigger and closer to Earth than we knew: 'The jury is still out on what it all means.' As the shock travels through the surrounding shell, magnetic fields ramp up to incredibly powerful energies. These magnetic fields take any random subatomic particles — the debris in the shell — and accelerate them, bouncing them back and forth within the shock wave. With every bounce, the particle gains more energy. Finally, it gets enough energy to leave the chaos altogether and stream into the universe. But within a few months, the system loses steam as the shock wave slows down. It still produces abundant cosmic rays, but not above the PeV threshold. This scenario explains why we haven't directly observed any active PeVatrons. Even though a supernova goes off in the Milky Way every few years, none have been close enough in modern times for us to observe the short window when they can accelerate cosmic rays to these extreme energies. So we'll just have to be patient.
Ya Biladi
14-02-2025
- Science
- Ya Biladi
Moroccan scientists help detect record-energy Neutrino in Mediterranean
On February 13, 2023, a groundbreaking achievement in astrophysics was recorded with the detection of a neutrino possessing an extraordinary energy level of approximately 220 petaelectronvolts (PeV). This significant discovery was made by the KM3NeT underwater telescope, situated 3,000 meters deep in the Mediterranean Sea, as explained to MAP by Prof. Yahya Tayalati, the national coordinator of the KM3NeT project in Morocco and a professor at Mohammed V University of Rabat, also affiliated with Mohammed VI Polytechnic University of Benguerir (UM6P). This discovery, published in the journal Nature, unveils new opportunities for understanding extreme astrophysical phenomena such as supermassive black holes and supernovas. Neutrinos, which are extremely light and neutral elementary particles, interact very weakly with matter, making them notoriously challenging to detect. These particles are generated during violent cosmic events and can traverse vast cosmic distances unaltered, serving as invaluable messengers for studying extreme astrophysical phenomena. The KM3NeT telescope represents an international research infrastructure, comprising a network of underwater detectors strategically distributed across two key sites in the Mediterranean: ARCA, focused on high-energy astronomy off the coast of Sicily, and ORCA, specializing in low-energy studies near Toulon. These detectors capture the light emitted during neutrino interactions with seawater, facilitating their detection and study. Collaboration of several Moroccan researchers Morocco has been a pivotal contributor to this international collaboration since 2016. The Moroccan consortium includes Mohammed V University of Rabat, Mohammed I University of Oujda, Cadi Ayyad University of Marrakech, and Mohammed VI Polytechnic University of Benguerir, with the National Center for Energy, Sciences and Nuclear Techniques (CNESTEN) participating as an observer member. The Kingdom has established two construction sites for KM3NeT, the only ones outside Europe : one at the Faculty of Sciences of Rabat, focusing on integrating digital optical modules to detect neutrinos' luminous trails, and another at the Faculty of Sciences of Oujda, dedicated to integrating electronics for communication with these modules. This active involvement underscores Morocco's commitment to advanced scientific research and provides opportunities for transferring cutting-edge technologies to the country, thereby enhancing the skills of Moroccan researchers and opening new avenues for young scientists.
