CERN Scientists Recreate Cosmic Fireballs to Study Gamma-Rays and Cosmic Jets

In a groundbreaking experiment, scientists at CERN have successfully recreated 'cosmic fireballs' to study high-energy gamma rays and cosmic jets. According to Space.com, this pioneering research was conducted by a collaborative team from the University of Oxford and the Science and Technology Facilities Council's Central Laser Facility.

Utilizing the Super Proton Synchrotron at CERN's HiRadMat facility, researchers generated electron-positron pairs and directed them through one meter of plasma, mimicking the extreme conditions found in the jets produced by supermassive black holes known as blazars.

Blazars are active galactic nuclei powered by black holes millions to billions of times the mass of our sun, surrounded by accretion discs of gas and dust. These black holes emit twin jets of plasma at nearly the speed of light, creating intense gamma-ray radiation that has been difficult to fully detect due to mysterious missing low-energy gamma rays.

These rays scatter off photons from the cosmic microwave background as they traverse intergalactic space, leading to the formation of matter and antimatter pairs. However, the expected detection of low-energy gamma rays has eluded space-based instruments such as the Fermi spacecraft.

The team at CERN sought to investigate potential explanations for this absence, including the possibility that weak intergalactic magnetic fields could deflect these gamma rays from our line of sight or that the matter-antimatter pairs may become unstable due to the sparse intergalactic medium.

In their experiments, the researchers were surprised to find that the plasma beam maintained its narrow shape with minimal disruption, which contradicts the idea that plasma instabilities could account for the missing gamma rays.

Instead, their findings may suggest the presence of a relic magnetic field existing in the intergalactic medium, raising further questions about its origins in the early universe. As noted by team member Bob Bingham, this research represents a significant advancement in laboratory astrophysics, enabling scientists to test theories about high-energy phenomena in the universe.

The team's results are documented in the journal PNAS, highlighting the potential for future investigations to explore fundamental cosmic questions and the mysteries of the universe's high-energy dynamics.