Astronomers have interpreted the oddly shaped objects in these NASA Hubble Space Telescope snapshots as strong visual evidence for multiple galaxies crashing into each other. These smashups create a tangled clump of matter and trigger a burst of new stars.
The photo at upper right, for example, appears to possess the nuclei of several galaxies. In another picture [bottom row, center], a three-galaxy collision has ripped several streamers of stars from their homes. The galaxies are converging into one central spot.
The Wide Field and Planetary Camera 2 pictures reveal a surprising amount of complexity and structure in these galaxies, called ultra-luminous infrared galaxies because they glow fiercely in infrared light. The bright, infrared glow is caused by a firestorm of star birth triggered by the multiple-galaxy pileups.
These images are part of a three-year study of 123 galaxies within 3 billion light-years of Earth. The study was conducted in 1996, 1997, and 1999. False colors were assigned to these photos to enhance fine details within these merging galaxies.
