Unlocking the Universe: How CERN is Recreating Cosmic Fireballs to Discover Missing Gamma Rays

Scientists have taken a big step in understanding the universe by recreating “cosmic fireballs” in a lab. They used a particle accelerator to simulate the extreme conditions found near supermassive black holes known as blazars. This experiment could help us learn about hidden magnetic fields and the puzzling absence of certain high-energy gamma rays.

Researchers from Oxford University and the Science and Technology Facilities Council teamed up at CERN’s HiRadMat facility. They created electron-positron pairs and blasted them through plasma, mimicking the gases ejected by blazars. According to Bob Bingham, a researcher involved in the project, these experiments let us test theories about high-energy cosmic events by reproducing those conditions in a lab.

Blazars are active galactic nuclei fueled by supermassive black holes that gobble up massive amounts of matter. Surrounding these black holes are swirling discs of gas and dust that shine brightly due to intense friction. As material falls into the black hole, some of it gets propelled out in twin jets at nearly the speed of light, creating strong gamma-ray emissions aimed at Earth.

These gamma rays should interact with background photons in space, producing lower-energy gamma rays detectable by space telescopes like the Fermi spacecraft. Yet, scientists have struggled to find these lower-energy emissions.

Several theories have emerged to explain this mystery. One suggests that weak magnetic fields between galaxies may deflect the gamma rays from our view. Another idea is that the matter-antimatter pairs lose stability during their journey, causing fluctuations that dissipate energy from the jets. Some even propose a relic magnetic field from the early universe could affect these gamma rays.

The recent experiment yielded unexpected results. Instead of spreading out as anticipated, the beam of particles maintained its narrow shape with minimal disruption. This finding might indicate that plasma beam instabilities are too weak to account for the missing low-energy gamma rays. It bolsters the hypothesis that an ancient magnetic field exists in the space between galaxies.

Interestingly, the concept of relic fields isn’t new. In the 1980s, scientists proposed these could linger from the Big Bang, influencing cosmic phenomena. Today, the implications of these experiments signal a need for deeper exploration into early universe physics, possibly through future facilities like the Cherenkov Telescope Array Observatory.

Expert Subir Sarkar noted the significance of this innovative experiment, which could inspire fresh insights within the plasma astrophysics community. The team’s findings were published in the journal PNAS, marking a notable contribution to our understanding of cosmic mysteries.

For more detailed insights, you can check out the study here.

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