Astronomers have discovered a vast cloud of energetic particles, dubbed a “mini halo,” surrounding one of the most distant galaxy clusters ever observed. The discovery, published in The Astrophysical Journal Letters, marks a major step forward in understanding the hidden forces that shape the cosmos.
The mini-halo is located at a distance so great that it takes light 10 billion years to reach Earth, making it the most distant ever found. It consists of highly energetic, charged particles emanating from a region of space filled with magnetic fields and radio waves detectable from Earth.
Researchers analyzed data from the Low Frequency Array (LOFAR) radio telescope, which revealed a faint, widespread radio signal that did not originate from individual galaxies but from a vast region of space. This diffuse glow stretches over a million light-years and is characteristic of a mini-halo.
“This discovery gives us a new window into how galaxy clusters grow and evolve, driven by both black holes and high-energy particle physics,” said Julie Hlavacek-Larrondo, co-lead researcher. The findings suggest that galaxy clusters have been immersed in high-energy particles for most of their existence, shaping the cosmos.
Two possible explanations behind the mini-halo’s formation are supermassive black holes ejecting streams of high-energy particles and cosmic particle collisions. Further study with newer telescopes like the Square Kilometer Array (SKA) will help uncover more about magnetic fields, cosmic rays, and energetic processes in the early universe.
The discovery provides a rare look at galaxy clusters just after they formed, revealing that these structures have been energized for billions of years longer than previously known. As scientists continue to explore the role of black holes and high-energy particle physics, they say they are “just scratching the surface” of understanding the hidden forces shaping the cosmos.
Source: https://phys.org/news/2025-06-discovery-mini-halo-early-universe.html