How do galaxies die?
1 Answer
Some galaxies die through collisions, others never really do.
Explanation:
Galaxies have very long life cycles. As many galaxies reside in groups and clusters, they collide every so often. In fact our Milky Way galaxy will collide with the Andromeda galaxy in about 4 billion years time.
When two galaxies collide, if they are both quite large they will merge into a single, usually elliptical galaxy. If one is much smaller it will be consumed by the larger galaxy and will effectively die.
The ultimate fate of all galaxies depends on the evolution of the universe. It is currently thought that the universe is continuing to expand. So, collisions between galaxies will ultimately stop.
What will happen is that star production will stop as the material to make new stars runs out. The stars themselves will all die. At this stage the galaxies will still exist but they will be dark.
