Until now, astronomers thought such powerful particle activity only happened later in cosmic history. However, this faint radio signal, spanning across a million light-years, proves that even the earliest galaxy clusters were teeming with energetic processes.

The finding could reshape our theories about black holes, cosmic collisions, and other hidden forces that have been driving cosmic evolution for billions of years.

Finding a halo 10 billion light-years away

Original image of the cosmic halo located 10 billion light years away in a galaxy cluster. Source: Chandra X-ray Center/NASA/CXC/ASTRON/LOFAR/SAO

Mini-halos are vast clouds of high-energy particles that sit between galaxies in a cluster. These charged and incredibly fast particles emit faint radio waves as they move through space. However, detecting such halos is extremely difficult, especially in the distant universe.

The farther something is, the fainter its signal becomes. Until this study, astronomers weren’t able to spot these structures more than a few billion light-years away. However, thanks to a powerful new tool called the Low Frequency Array (LOFAR), this time, scientists detected a halo located 10 billion light years away.