According to Phys.org, an international team led by the University of Oxford has achieved a world-first by creating plasma “fireballs” using CERN’s Super Proton Synchrotron accelerator in Geneva. The research, published in PNAS, focused on studying plasma jets from blazars—active galaxies powered by supermassive black holes that emit intense gamma-ray radiation up to several teraelectronvolts. Scientists investigated why these gamma rays, after scattering off intergalactic light to create electron-positron pairs, fail to produce the expected lower-energy gamma rays detectable by telescopes like the Fermi satellite. The experiment revealed that beam-plasma instabilities are too weak to explain the missing radiation, pointing instead to deflection by primordial intergalactic magnetic fields dating back to the early universe.
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The Dawn of Laboratory Astrophysics
This research represents a paradigm shift in how we study cosmic phenomena. For decades, astrophysics has been largely observational—we could only watch what the universe showed us. Now, with facilities like CERN’s HiRadMat, we’re entering an era where we can recreate cosmic conditions in controlled laboratory settings. The ability to generate electron-positron pairs and study their behavior through meter-long plasma chambers gives us unprecedented experimental control over processes that were previously only theoretical. This bridges the gap between computer simulations and actual observations, providing ground truth for models that have guided our understanding of high-energy astrophysics for generations.
The Primordial Magnetic Field Discovery
The finding that intergalactic space contains relic magnetic fields from the early universe has profound implications for cosmology. These fields likely originated during the universe’s first moments, potentially during inflation or phase transitions that occurred fractions of a second after the Big Bang. The persistence of these fields across billions of years suggests they played a crucial role in shaping cosmic structure formation, potentially influencing how galaxies clustered and evolved. More importantly, the strength and distribution of these fields could provide clues about physics beyond the Standard Model, as their origin remains unexplained by current theories. The research published in PNAS indicates we may need to revise our understanding of the early universe’s uniformity.
Accelerator Science Meets Astrophysics
This breakthrough demonstrates the expanding applications of particle accelerator technology beyond traditional high-energy physics. Facilities like CERN’s Super Proton Synchrotron, originally designed for fundamental particle research, are now becoming multi-disciplinary platforms for astrophysical experimentation. This cross-pollination benefits both fields—astrophysicists gain experimental capabilities previously unimaginable, while accelerator scientists find new applications for their technology. The success of this collaboration between the University of Oxford and STFC’s Central Laser Facility suggests we’ll see more such partnerships, potentially leading to dedicated beamlines for astrophysical research at major accelerator facilities worldwide.
The Coming Revolution in Gamma-Ray Astronomy
The findings create exciting anticipation for next-generation observatories, particularly the Cherenkov Telescope Array Observatory (CTAO). With higher resolution and sensitivity, CTAO will be able to test the magnetic field hypothesis directly by searching for the telltale signatures of deflected gamma rays. This laboratory result provides a clear prediction that observational astronomers can now test—if the magnetic field explanation is correct, we should see specific patterns in gamma-ray distributions that previous telescopes couldn’t resolve. The convergence of laboratory experiments and advanced observatories creates a powerful feedback loop where each informs and validates the other, accelerating our understanding of high-energy cosmic processes.
Beyond Gamma Rays: Ripple Effects Across Physics
This research has implications far beyond explaining missing gamma rays. The demonstration that beam-plasma instabilities are insufficient to disrupt relativistic jets affects our understanding of various cosmic phenomena, from quasar emissions to gamma-ray bursts. It suggests that magnetic fields play a more dominant role in cosmic particle transport than previously appreciated. Additionally, the techniques developed for this experiment could be applied to other astrophysical puzzles, such as the acceleration mechanisms of cosmic rays or the dynamics of solar flares. The ability to recreate extreme astrophysical conditions in the laboratory opens new avenues for testing theories across multiple domains of physics, potentially leading to breakthroughs we can’t yet anticipate.
