Hot, low-density gas can be detected in galactic clusters through X-ray emission. The gas is important in understanding dark matter because ____.
A) dark matter is responsible for heating the gas
B) dark matter must make the cluster massive enough to hold on to the hot gas
C) the gas may be the source of dark matter
D) the gas is clumped in empty places between galaxies where there is more dark matter
E) the gas is produced by dark matter

Question

Quizplus · Accepted Answer

Dark matter's gravitational pull is necessary to explain the mass and gravitational forces required to keep the hot, low-density gas within the gravitational bounds of galactic clusters. The presence and behavior of this gas, observable through X-ray emissions, indirectly indicate the presence and influence of dark matter, as normal baryonic matter alone (such as stars and gas) cannot account for the gravitational forces at play.

Hot, Low-Density Gas Can Be Detected in Galactic Clusters Through