In active galaxies, their central engines may be temporarily fed by
A) a close encounter with a neighbor galaxy.
B) a sudden surge of star formation.
C) the sudden collapse of the core into a supermassive black hole.
D) the fusion of helium into carbon in their cores.
E) a series of supernovae around the core.

Question

Quizplus · Accepted Answer

Active galaxies are often powered by material falling into a supermassive black hole at their center. A close encounter with a neighboring galaxy can disturb the gas and dust in a galaxy, funneling material towards the center and temporarily feeding the central engine.

In Active Galaxies, Their Central Engines May Be Temporarily Fed