Galaxy merger (artist's impression)

This artist’s impression shows the merger between two galaxies leading to the formation of a disc galaxy. Upon merging, the shape of the galaxies is disturbed by their mutual gravitational interaction and results in a galaxy with a disc structure. Gas that is moving away from us appears red while the blue colour shows gas that is approaching. The contours together with the transition from red to blue indicate a gaseous disc that is rotating about the centre of the galaxy.

The movie shows the collision of two disc galaxies, but the actual shape of galaxies prior to the collision in this study is not known.