The Abell 1689 Galaxy cluster.
A massive supercluster of individual galaxies in the constellation of Virgo – at a distance of over 2 billion light years.
The light from many of the most distant galaxies, behind the cluster appear distorted and streched in arcs. Some of these most distant distant galaxies are as far as 13 billion light years away.
This distortion of light from the back ground galaxies is due to gravitational lensing caused by the mass of the forground supercluster & the presence of dark matter along the line of sight.
The dark matter concentration is super-imposed in blue.
There is now also evidence gasses super heated to temperatures in excess of 100 million degrees within the cluster.