Le télescope Dampe révèle un modèle universel dans les rayons cosmiques

14 mai 2026

Rapporté par l'IA

Des chercheurs utilisant le télescope spatial DAMPE ont identifié un adoucissement spectral commun dans les rayons cosmiques à travers plusieurs types de particules. Ce modèle apparaît à une rigidité d'environ 15 téraélectronvolts pour les protons ainsi que pour les noyaux de fer. Cette découverte, publiée dans la revue Nature, offre un nouvel éclairage sur le comportement de ces particules à haute énergie dans la galaxie.

Depuis plus d'un siècle, les scientifiques étudient les rayons cosmiques, les particules les plus énergétiques connues dans la nature. Les données de la mission DAMPE, lancée en décembre 2015, montrent désormais que le nombre de ces particules chute brutalement au-delà d'un seuil de rigidité commun. Cet effet s'observe aussi bien pour les protons que pour les noyaux d'hélium, de carbone, d'oxygène et de fer.

Articles connexes

New model proposes dark matter made of two particles to explain Milky Way gamma-ray excess

Building on prior detections of gamma-ray emissions from the Milky Way's center, physicists led by Gordan Krnjaic at Fermilab propose dark matter consists of two distinct particles that interact to produce detectable signals. This resolves the puzzle of signals in the Milky Way but none in dark-matter-rich dwarf galaxies, as observed by the Fermi Gamma-ray Space Telescope.

Physicists link extreme neutrino to exploding primordial black hole

8 avril 2026 Rapporté par l'IA

Physicists at the University of Massachusetts Amherst propose that a record-breaking neutrino detected in 2023 originated from the explosion of a primordial black hole carrying a 'dark charge.' The particle's energy, 100,000 times greater than that produced by the Large Hadron Collider, puzzled scientists since only the KM3NeT experiment recorded it. Their model, published in Physical Review Letters, could also hint at the nature of dark matter.

Science

Gravitational waves may have created early universe dark matter

Science

Scientists capture metal turning into star-like plasma in trillionths of a second

Science

Researchers reduce uncertainty in cosmic birefringence measurements

Astronomers solve gamma-Cas X-ray mystery after 50 years

Astronomers have identified the source of unusual X-rays from the bright star gamma-Cas as a hidden white dwarf companion siphoning material from it. High-resolution data from the XRISM space mission confirmed that the emissions arise from matter heating up as it falls onto the unseen star. The discovery ends a puzzle that has intrigued scientists since the 1970s.

Scientists unveil camera capturing trillionth-of-a-second events

21 avril 2026 Rapporté par l'IA

Researchers at East China Normal University have developed a new imaging technique that captures ultrafast events in trillionths of a second, revealing both brightness and structural changes in a single shot. The method, called compressed spectral-temporal coherent modulation femtosecond imaging (CST-CMFI), tracks phenomena like plasma formation and electron movement. Yunhua Yao, the team leader, described it as a major advance for physics, chemistry, and materials science.

jeudi 14 mai 2026 14h22