An astronomer discovers a massive galaxy which has four nuclei. What is a likely explanation for a galaxy having more than one nucleus?
A) the nuclei of galaxies often split into two or more parts because of internal activity
B) the galaxy must have been a quasar earlier in its life
C) the galaxy must have swallowed several smaller galaxies that were its neighbors
D) the galaxy must have had an unusual number of supernova explosions
E) astronomers have no explanation for multiple nuclei in galaxies; it's baffling

Question

Quizplus · Accepted Answer

Multiple nuclei in a galaxy are often the result of merging with smaller galaxies, leading to the presence of multiple supermassive black holes at the centers of the merged galaxies.

An Astronomer Discovers a Massive Galaxy Which Has Four Nuclei