A very energetic Galactic particle accelerator

• 成果类型: Editorial Material
• 署名作者: Bosch-Ramon, Valenti
• 署名单位: Institut d'Estudis Espacials de Catalunya (IEEC)
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-14054
• DOI: 10.1126/science.adn3487
• 发表日期: 2024-01-26
• 页码: 371-372
• 关键词: x-ray-spectrum; cosmic-rays; jets; microquasars; radiation

摘要

The most powerful plasma jets in the Milky Way emit very-high-energy gamma rays Since the 1912 discovery of cosmic rays (1), the origin of these extremely energetic particles has remained a mystery. Remnants of a star explosion (supernova) have been considered dominant sources of cosmic rays (2), at least for those originating in the Milky Way, but this may not be true at energies approaching peta-electron volts (1 PeV = 10(15) eV) (3, 4). Microquasars may also generate cosmic rays (5, 6), but evidence has been scarce. These systems consist of a star and either a black hole or neutron star. Ionized matter (plasma) is emitted as jets flowing in opposite directions from the microquasar. On page 402 of this issue, the High Energy Stereoscopic System (H.E.S.S.) Collaboration (7) reports the detection of extremely energetic gamma rays produced in the large-scale jets of SS 433, the most powerful microquasar in the Milky Way. Thus, microquasars may indeed contribute to the most energetic Galactic cosmic rays.