... galaxies . ... Four spiral galaxies in Leo . ... A galactic crash investigation . ... This image combines visible light exposures of galaxy cluster Abell 2744 taken by the NASA/ESA Hubble Space Telescope and the European Southern Observatoryт??s Very Large Telescope, with X-ray data from NASAт??s Chandra X-ray Observatory and a mathematical reconstruction of the location of dark matter. ... In another part of the cluster, there seem to be galaxies and dark matter, but no hot gas. ...