Chandra Release - October 30, 2008

Visual Description: Bullet Cluster

The image showcases an X-ray and optical image of the Bullet Cluster, which is a galaxy cluster located about 3.8 billion light-years away. The image is dominated by soft red-pink colors, which represent the presence of hot gas in the cluster.  The image shows a vast collection of galaxies and some foreground stars on a dark background. The shape of the Bullet Cluster resembles a bullet, hence its name, with a peak of hot gas serving as the bullet's nose. This unique shape is caused by the collision between two galaxy clusters, which resulted in the formation of the Bullet Cluster.   The optical image shows the galaxies in the Bullet Cluster and the X-ray image (soft red) reveals how much hot gas has collided. If some of the gas from either cluster has particles of antimatter, then there will be annihilation between the matter and antimatter and the X-rays will be accompanied by gamma rays.