Most active galactic nuclei are found at large distances from us,with relatively few nearby.What does this imply?
A)Supermassive black holes existed only when the universe was young,and no longer exist today.
B)Active galactic nuclei can form only at large distances from the Milky Way.
C)Active galactic nuclei exist tend to become less active as they age.
D)The jets seen in many active galactic nuclei must cause them to move far away from us.

Question

Quizplus · Accepted Answer

This implies that active galactic nuclei (AGN) tend to become less active over time. The fact that most AGNs are found at large distances means we are observing them as they were in the past, due to the time it takes for their light to reach us. This suggests that when the universe was younger, AGNs were more common and active, but as they age, they become less active, which is why fewer are found nearby in the more recent universe.

Most Active Galactic Nuclei Are Found at Large Distances from Us,with