Astronomers have identified the cause of a unique formation of radio waves, dubbed the “Treble Clef,” using NASA’s Chandra X-ray Observatory. The shape of this formation closely resembles the musical symbol, which has helped capture the interest of the scientific community.
Formation Discovery
According to a study led by Andrea Botteon from Italy’s National Institute for Astrophysics, the Treble Clef is likely the result of an outburst from a supermassive black hole, followed by a collision between two galaxy clusters. The findings were published in the Astronomy & Astrophysics journal on Wednesday.
The Treble Clef’s location poses a challenge for observation, lying almost directly behind the plane of the Milky Way, obscured by stars, gas, and dust. To overcome this, researchers utilized telescopes capable of penetrating the intervening material to ascertain the cause of this unusual structure.
X-ray and Radio Data Analysis
Chandra, along with the eROSITA X-ray telescope, detected diffuse, hot gas at the formation’s location, indicating the presence of a galaxy cluster. The analysis revealed that this cluster consists of two merging clusters, which are among the universe’s largest structures, containing vast numbers of galaxies and reservoirs of superheated gas.
The researchers created a composite image of the Treble Clef, showing the multimillion-degree gas in blue, while radio data from the LOw Frequency ARray (LOFAR) depicted the treble clef formation in red. Infrared data from the United Kingdom Infrared Telescope appeared mostly white in the final image.
Two-Stage Formation Process
The authors proposed that the Treble Clef formed through a two-stage process. Initially, an outburst from a supermassive black hole propelled charged particles and magnetic fields at nearly light speed, generating bright radio waves that later diminished as the particles lost energy. The subsequent collision of the two galaxy clusters compressed or reenergized this particle cloud, resulting in a resurgence of bright radio waves. Shock waves from the collision may have contributed to this reenergizing.
To investigate the cluster collision within the Chandra data, the team employed a technique to examine deviations from a symmetrical shape in the hot gas. The analysis showed that the remaining X-ray emission was brightest on the edges, suggesting the collision occurred along a left-right axis as seen in the image.
Scientific Implications
The researchers estimate that the collision between the two clusters likely took place hundreds of millions of years ago, with the clusters now moving apart. The resemblance of the formation to a treble clef is attributed to pareidolia, the tendency of people to recognize familiar shapes in random data, rather than having any scientific connection to music.
NASA’s Marshall Space Flight Center in Huntsville, Alabama, oversees the Chandra program, while the Smithsonian Astrophysical Observatory manages its science operations from Cambridge, Massachusetts.
Source: NASA
