Hubble sees 'Comet Galaxy' being ripped apart by galaxy cluster

An extended view of the Hubble image also shows the gravitational lensing effect -- an optical illusion -- caused by the cluster's gravitational tidal forces of the cluster and "ram pressure stripping" by the hot gas. The strong gravitational pull exerted by the galaxy cluster’s collective mass has also bent the light of distant galaxies, distorting their shapes. A giant luminous blue arc corresponds to the distorted image of a galaxy that lies behind the cluster’s core. This effect resembles the so-called caustic pattern of light ripples observed when looking at a sandy bottom as light is focused by the wave crests and valleys. In the gravitational lens here, the yellow cluster galaxies act as wave crests whereas the banana-shaped arcs are the caustic patterns created by the focusing power of the matter cluster. Cluster Abell 2667 is a massive luminous galaxy cluster located (z = 0.233) 3.2 x 10^9 light-years from Earth. It is a richness class-3 (130-199 galaxy members) in the Abell catalogue. It hosts an extremely bright giant gravitational arc easily identifiable as part of a triple image system where other much fainter multiple images are also revealed. The presence of a giant luminous arc points out the presence of a very dense cluster core. The discovery of the "Comet Galaxy" falling in towards the cluster core is a direct evidence of the strong influence of cluster's environment on the evolution of spiral galaxies. Credit: NASA, ESA, Jean-Paul Kneib (Laboratoire d’Astrophysique de Marseille)