• Astronomers discovered a pair of exceptionally large radio relics in galaxy cluster PSZ2 G181.06+48.47.
• The radio relics are believed to have formed due to shockwaves resulting from a collision between two galaxy groups.
• The discovery hints at a cluster merger in its final stages, potentially revealing more such relics with advanced telescopes.

A team of astronomers has identified a pair of rare radio relics within the galaxy cluster PSZ2 G181.06+48.47, located approximately 963 million light-years away. These relics, gigantic arcs of radio energy spanning 11 million light-years, are thought to be the result of shockwaves created by the collision of two galaxy groups. The discovery offers insights into the dynamics of galaxy cluster mergers and the formation of radio halos, potentially leading to the identification of more such structures with future telescopes.

• What: Discovery of a pair of radio relics, large arcs of radio energy, flanking the galaxy cluster PSZ2 G181.06+48.47.
• Who: Kamlesh Rajpurohit (Harvard & Smithsonian Center for Astrophysics) led the research team. Telescopes used were the Giant Metrewave Radio Telescope in India and the Very Large Array in New Mexico.
• When: The relics suggest the cluster is in the final stages of a merger that started a billion years ago. The discovery was updated on May 7, 2025.
• Where: The galaxy cluster PSZ2 G181.06+48.47 is located approximately 963 million light-years from Earth.

The discovery of these radio relics is significant because they are exceptionally large and rare, providing valuable insights into the energetic processes involved in galaxy cluster mergers. The relics' formation, driven by shockwaves resulting from the collision of galaxy groups, illuminates the dynamics of these cosmic events. The potential for future telescopes like the Square Kilometre Array to uncover more relics suggests that these structures are more common than previously thought, promising a deeper understanding of the universe's large-scale structure and evolution.

Until that time, you can call it Planck cluster G181+48 for short.

The detection of these record-breaking radio relics offers a glimpse into the energetic phenomena occurring during galaxy cluster mergers. Their size and unique characteristics contribute to a growing understanding of the universe's most massive structures. Future observations with advanced telescopes hold the potential to reveal a wealth of similar relics, further unraveling the complexities of cosmic collisions and the formation of large-scale structures.