Chandra Observatory links Treble Clef radio formation to galaxy cluster collision

Astronomers have identified the cause of a unique radio wave formation nicknamed the ‘Treble Clef’ due to its resemblance to a musical symbol. Using data from NASA’s Chandra X-ray Observatory, the United Kingdom Infrared Telescope, and Europe’s LOw Frequency ARray (LOFAR), researchers determined the structure was created by a supermassive black hole outburst followed by a collision between two galaxy clusters.

The formation is located almost directly behind the plane of the Milky Way, making it difficult to observe due to obstruction from galactic gas, dust, and stars. By combining X-ray, radio, and infrared data, scientists confirmed the presence of superheated gas, proving the object resides within a galaxy cluster. Further analysis revealed that two separate clusters are currently merging.

The study, led by Andrea Botteon of Italy’s National Institute for Astrophysics, suggests the formation occurred in two stages: an ancient black hole outburst propelled charged particles into space, and a subsequent cluster collision—likely occurring a few hundred million years ago—re-energized these particles through shock waves or compression, making them visible in radio waves once more.