Cosmic threesomes make some galaxies run away
Compact ellipticals orphaned by collision with intruder
ORPHAN MAKER In this artwork, an "intruder" spiral galaxy (left and middle, red path) sidles up to a galaxy cluster where a compact elliptical revolves (cE orbit, blue path) next to its host, kicking the compact elliptical out of orbit before being devoured itself by the giant galaxy in the cluster center (right).
I. Chilingarian; images courtesy NASA, ESA, HubbleHeritage Team (STScI/AURA)