A z=0.9 supercluster of X-ray luminous, optically-selected, massive galaxy clusters

Understand

We report the discovery of a compact supercluster structure at z=0.9.

• The structure comprises three optically-selected clusters, all of which are detected in X-rays and spectroscopically confirmed to lie at the same redshift.
• The Chandra X-ray temperatures imply individual masses of ~5x10^14 Msun.
• The X-ray masses are consistent with those inferred from optical--X-ray scaling relations established at lower redshift.