A Galaxy Cluster’s Wild Youth

The galaxy cluster Abell 2029 is sometimes described as “the most relaxed cluster in the Universe.” This moniker does not arise from some sort of mellow vibe, but rather because of how calm and undisturbed the superheated gas that pervades the cluster appears to be. But new Chandra X-ray observations of the massive cluster highlight a major merger 4 billion years ago that still shape it today.