Composite optical image of two clusters of galaxies Abell 222 and Abell 223 with a dark matter map overlayed in blue shading and yellow contours. The two clusters are connected by a filament of dark matter. The optical image was obtained by SuprimeCam at the Subaru telescope. The mass map is based on the gravitational lensing signal of more than 40,000 background galaxies.
This work by Jörg Dietrich, University of
Michigan/University Obervatory Munich is licensed under a
Creative
Commons Attribution-ShareAlike 3.0 Unported License.