Evidence for dark matter surrounding massive galactic clusters comes from what observation?
A)Huge galactic jets that contain large quantities of dark matter.
B)Motions of individual galaxies toward an invisible gravitational source.
C)Colliding neutron stars,with the collision energy creating dark matter.
D)Arcs caused by a gravitational deflection of light.

Question

Quizplus · Accepted Answer

The observation of arcs caused by a gravitational deflection of light, known as gravitational lensing, is evidence for the presence of dark matter surrounding massive galactic clusters. The lensing occurs because the gravitational pull of the dark matter bends the path of light, causing the arcs to form. Option A is not correct, as galactic jets do not contain dark matter, but are powered by high-energy particles emitted by active galactic nuclei. Option B is partially correct, as the motions of galaxies can be affected by the gravitational pull of unseen matter, but it does not necessarily imply the presence of dark matter specifically. Option C is not correct, as the collision of neutron stars does not create dark matter.

Evidence for Dark Matter Surrounding Massive Galactic Clusters Comes from What