ESA Science & Technology - Sky surveys: mapping dark and ordinary matter

This image is the first large-scale map of the dark matter and baryon distributions in the universe. The distribution of normal matter (in red) was determined mainly by XMM-Newton, dark matter (in blue) and stars and galaxies (in grey) were observed in the optical band with the Hubble telescope.  All the baryons observed by XMM-Newton are located within dark matter clumps and filaments. This means that normal matter, mostly in the form of galaxies, accumulates along the densest concentrations of dark matter and that the galaxies and clusters of galaxies are assembled inside a dark matter scaffolding. This map is an important cosmological result and it confirms conventional theories where the filamentary structure of the Universe was formed under the pull of gravity.