Dark Matter Mystery Deepens in Cosmic "Train Wreck"
Abell 520 – click for 792×792 image
Additional information: here, here, here, here, here
This multi-wavelength image of Abell 520 shows the aftermath of a complicated collision of galaxy clusters, some of the most massive objects in the Universe. In this image, the hot gas as detected by Chandra is colored red. Optical data from the Canada-France-Hawaii and Subaru telescopes shows the starlight from the individual galaxies (yellow and orange). The location of most of the matter in the cluster (blue) was also found using these telescopes, by tracing the subtle light-bending effects on distant galaxies. This material is dominated by dark matter.
Abell 520 – click for 792×792 image
Additional information: here, here, here, here, here