The central regions of large clusters contain mostly S0 and elliptical galaxies.Why?
A)Tides there have stripped normal spirals of their outer parts
B)Galaxies are still forming there
C)They are too distant for us to see other types of galaxies
D)S0 galaxies are shot out of other galaxies in clusters

Question

Quizplus · Accepted Answer

The tidal forces in the central regions of large clusters are very strong, stripping the outer parts of spiral galaxies and leaving them as S0 or transforming them into elliptical galaxies. This process is known as "galaxy harassment" and is a result of the gravitational interactions between galaxies in the dense environment of a cluster.

The Central Regions of Large Clusters Contain Mostly S0 and Elliptical