A giant wave spanning 200,000 light years, dubbed an ‘X-ray tsunami’, is rolling through the Perseus Galaxy Cluster, as captured in this video based on images taken by NASA’s Chandra X-ray Observatory.
Galaxy clusters are the largest gravity-bound structures in the universe: Perseus measures 11 million light-years across.
Clusters are made predominantly of gas with temperatures higher than 100 million degrees Celsius – so hot it’s only visible through X-ray imagery.
“Perseus is one of the most massive nearby clusters and the brightest one in X-rays, so Chandra data provide us with unparalleled detail,” says Stephen Walker at NASA’s Goddard Space Flight Center in Maryland, USA.
“The wave we’ve identified is associated with the flyby of a smaller cluster, which shows that the merger activity that produced these giant structures is still ongoing.”
By flying too close to Perseus’ core, a smaller cluster has disturbed the cooler gas in the centre of the structure, which has then spiraled outwards creating a wave that will continue to roll around Perseus for hundreds of millions of years before it dissipates.
The researchers say clusters like Perseus probably experience merger events like this every few billion years.