Credit: X-ray: NASA/CXC/MIT/M. Calzadilla; UV/Optical/Near-IR/IR: NASA/STScI/HST; Image processing: N. Wolk

SPT-CL J2215-3537 (SPT2215 for short) is the most distant “relaxed” cluster of galaxies ever found, meaning that it shows no signs of having been disrupted by violent collisions with other clusters of galaxies. This composite image contains X-rays from Chandra (blue), which helped identify SPT2215 along with other telescopes, and data from Hubble (cyan and orange). Before this, astronomers were not sure relaxed clusters existed at this epoch of the universe, because they are usually still merging with other clusters or groups of galaxies as they increase in size.

Provider: Chandra X-ray Observatory

Image Source: http://chandra.harvard.edu/photo/2023/spt2215/

Curator: Chandra X-ray Observatory, Cambridge, MA, USA

Image Use Policy: http://chandra.harvard.edu/photo/image_use.html