Chandra Release - September 6, 2001

Visual Description: Galaxy Clusters and Dark Energy

This four panel montage shows two sets of Chandra X-ray Observatory images (on the left) and Hubble Space Telescope images (on the right) of the giant galaxy clusters Abell 2390 and MS2137.3-2353. The X-ray emission comes from the multimillion-degree gas that fills the clusters. Chandra's X-ray vision paints a bright canvas of superheated gas in vibrant textured clumps of red, yellow, and orange, on a black background. On the other side, the Hubble Space Telescope's optical gaze captures numerous galaxies, brightly colored in green, blue and yellow, with light bending in luminous arcs sculpted by the fabric of space and time.  Chandra provides detailed temperature maps for this gas and allows astronomers to precisely determine the masses of the clusters. Most of the mass is in these galaxy clusters are in the form of dark matter, a mysterious substance that does not interact with light.