Inside of galaxy clusters, which of these components contains about twice as much mass as the stars inside the cluster's galaxies?
A) large numbers of cool, dark, brown dwarf stars floating in the galaxy cluster
B) very hot intergalactic gas emitting X-rays in clusters.
C) a tremendous flux of neutrinos, which have recently been shown to have mass, coming from these clusters.
D) large numbers of small but massive black holes within every galaxy.

Question

Quizplus · Accepted Answer

The very hot intergalactic gas emitting X-rays in clusters contains about twice as much mass as the stars inside the cluster's galaxies. This gas is a major component of the total mass of galaxy clusters, significantly outweighing the mass in stars.

Inside of Galaxy Clusters, Which of These Components Contains About