A new record for the most distant galaxy cluster has been set using NASA’s Chandra X-ray Observatory and other telescopes. CL J1001+0220 is located about 11.1 billion light-years from Earth. The discovery of this object pushes back the formation time of galaxy clusters — the largest structures in the universe held together by gravity — by about 700 million years.
An international team of astronomers used European Southern Observatory telescopes to complement other earth- and space-based instruments as part of the XXL survey of galaxy clusters. The ESO team measured the precise distances to the galaxy clusters, providing the 3-D view of the cosmos required to perform accurate measurements of dark matter and dark energy.