Tour: Untangling a Knot of Galaxy Clusters

Astronomers have captured a spectacular and ongoing collision between at least three galaxy clusters. Data from NASA’s Chandra X-ray Observatory, ESA’s XMM-Newton and a trio of radio telescopes are helping astronomers sort out what is happening in this jumbled scene.

Galaxy clusters are some of the largest structures in the Universe and contain a mixture of galaxies, hot gas and dark matter. Over time, these colossal objects can collide and merge with each other through their gravitational pull. This is the main way that galaxy clusters can grow into the gigantic cosmic edifices seen today.

Abell 2256, located 780 million light years from Earth, is a scene where this process is taking place. Astronomers studying this object are trying to tease out what has led to this unusual-looking structure. Each telescope tells a different part of the story. For example, Chandra and XMM-Newton can see the multi-million-degree gas from the clusters. The radio emission in this system arises from an even more complex set of sources.

The first are the galaxies themselves, where the radio signal is generated by particles blasting away in jets from supermassive black holes at their centers. Radio waves are also coming from a huge filamentary structure, which was likely generated when the collision created shock waves and accelerated particles in the gas.

Astronomers will continue to study this complex system to untangle this knot of galaxy clusters and the details of the physics taking place there. This will help us learn more about how these cosmic giants came to inhabit the Universe today.