Chandra Release - December 16, 2008

Visual Description: Abell 85

On the left of this graphic, an image features X-ray and optical data of a galaxy cluster called Abell 85. The dominant colors in the image are rich purple and soft lavender, which represent the presence of hot gas in the galaxy cluster.  The shape of the galaxy cluster is roughly circular with a slight extended area below it like a very wide exclamation mark.  The purple emission is multi-million degree gas detected in X-rays by NASA's Chandra X-ray Observatory and smaller white specks show galaxies in an optical image from the Sloan Digital Sky Survey.  On the right of this graphc are three snapshots from a simulation by Volker Springel, representing the growth of cosmic structure when the Universe was 0.9 billion, 3.2 billion and 13.7 billion years old (now). This simulation shows how the Universe has evolved from a smooth state to one containing a vast amount of large filamentary-like structure. Gas is shown in these snapshots, where tiny yellow regions are stars and the brightest structures are galaxies and galaxy clusters. The growth of these structures was initially driven only by the attractive force of gravity, but then later there was competition with the repulsive force of dark energy.