Credit: ESA/Hubble & NASA
It is known today that merging galaxies
play a large role in the evolution of galaxies and the formation of
elliptical galaxies in particular. However there are only a few merging
systems close enough to be observed in depth. The pair of interacting
galaxies picture seen here — known as NGC 3921 — is one of these systems.
NGC 3921 — found in the constellation of Ursa Major
(The Great Bear) — is an interacting pair of disc galaxies in the late
stages of its merger. Observations show that both of the galaxies
involved were about the same mass and collided about 700 million years
ago. You can see clearly in this image the disturbed morphology, tails
and loops characteristic of a post-merger.
The clash of galaxies caused a rush of star formation and previous Hubble observations showed over 1000 bright, young star clusters bursting to life at the heart of the galaxy pair.
Source: ESA/Hubble - Space Telescope