Many rich, regular clusters of galaxies contain substantial amounts of very hot, intergalactic gas. What is believed to have produced this hot gas?
A) collisions between galaxies in the cluster
B) bursts of star formation in merging galaxies
C) supernovae (exploding stars)
D) jets of gas ejected by supermassive black holes at the centers of the galaxies

Question

Quizplus · Accepted Answer

The hot intergalactic gas in rich galaxy clusters is primarily believed to be produced by collisions between galaxies in the cluster. These collisions can strip gas from the galaxies, heating it to high temperatures as it falls into the cluster's gravitational potential well.

Many Rich, Regular Clusters of Galaxies Contain Substantial Amounts of Very