NASA’s Chandra Spots Champagne Cluster Formed by a Massive Galaxy Collision

The galaxy cluster discovered on New Year's Eve 2020 has been named the Champagne Cluster due to its bubble-like features and its date of discovery. The actual composite image, which is a mixture of the X-ray images taken by the Chandra Observatory of NASA and the surveys in visible light, indicates that the two galaxy clusters are actually colliding. The discovery was made by a team of UC Davis astronomers in The Astrophysical Journal, covering how galaxy cluster mergers are revealed even when using X-ray and optical light.

A Cosmic Collision

According to the paper, astronomers used Chandra's X-ray vision to probe the superheated gas in the cluster. Normally, gas in clusters appears as a roughly circular halo, but here it is stretched vertically, betraying the presence of two sub-clusters in collision. The image shows two clumps of galaxies flanking a purple cloud of multimillion-degree gas. This gas outweighs the total mass of the visible galaxies, and the clusters also contain a much larger amount of unseen dark matter.

Probing Dark Matter

Computer models indicate that these clusters likely collided more than 2 billion years ago and then came back together, or they might have had a single collision around 400 million years ago. Either way, looking into the Champagne Cluster could give scientists a better grasp of how dark matter acts during fast collisions. If we can see how dark matter either separates or stays with regular matter in these situations, researchers could uncover important insights about this mysterious stuff that makes up most of the universe.