耀变体喷流等离子体“火球”在实验室重现 有助破解“消失的伽马射线”之谜

Core Insights - An international team led by the University of Oxford has successfully created a plasma "fireball" in a laboratory setting using CERN's Super Proton Synchrotron, simulating the process of quasar jets propagating through interstellar space, providing new clues to the mystery of "missing gamma rays" in the universe [1][2] Group 1: Research Findings - Quasars, driven by supermassive black holes, emit narrow, near-light-speed jets of particles and radiation, producing extremely high-energy gamma rays, which can reach several TeV [1] - Theoretical models suggest that these high-energy gamma rays scatter with background starlight in interstellar space, generating electron-positron pairs, which should interact with cosmic microwave background to produce lower-energy gamma rays that have not been detected by satellite telescopes [1][2] Group 2: Experimental Methodology - To test existing theories, the research team utilized CERN's high-radiation materials facility to generate electron-positron pairs and allowed them to pass through a one-meter-long plasma, creating an experimental model of quasar jet propagation in interstellar space [2] - The experiment measured particle beam morphology and magnetic field signals, directly testing whether "jet-plasma instability" could disrupt the jet structure [2] Group 3: Conclusions and Implications - The experiment demonstrated that the particle beam maintained a narrow, nearly parallel shape with minimal disturbances or spontaneous magnetic fields, suggesting that instability effects are too weak to explain the missing low-energy gamma rays [2] - This finding supports the hypothesis that extremely weak interstellar magnetic fields, possibly remnants of the early universe's "primordial magnetic field," exist [2] - The research represents a significant step in understanding high-energy astrophysical jets and the origins of magnetic fields, with future observational facilities like the Cherenkov Telescope Array expected to provide higher resolution data to further validate these theories [2]