Astronomers Use NASA’s Chandra Observatory to Explain the Formation of the Treble Clef Galaxy Cluster Collision

Astronomers have used NASA’s Chandra X-ray Observatory to explain a rare radio wave formation dubbed the “Treble Clef” due to its striking resemblance to the musical symbol. Led by Andrea Botteon of Italy’s National Institute for Astrophysics, the research team published their findings Wednesday in Astronomy & Astrophysics.

The formation sits almost directly behind the Milky Way, blocking standard views from Earth. Researchers bypassed this obstacle by combining data from multiple telescopes. NASA’s Chandra and the German eROSITA telescope mapped hot gas to confirm the region is a merging galaxy cluster. European radio telescopes revealed the musical shape, while infrared data from the United Kingdom Infrared Telescope added surrounding stars.

Scientists conclude the Treble Clef formed in two stages. First, a supermassive black hole launched charged particles and magnetic fields, creating radio waves that eventually faded. Later, a collision between two galaxy clusters compressed and reenergized the clouds, causing the radio waves to brighten again. Researchers used a specialized imaging technique to isolate asymmetrical hot gas emissions, revealing that the cluster collision occurred along a left-right axis a few hundred million years ago.