Author Question: Why do almost all active galaxies occur in clusters of galaxies? What will be an ideal ... (Read 78 times)

BRWH · **on:** Jul 27, 2018

Why do almost all active galaxies occur in clusters of galaxies?

What will be an ideal response?

Question 2

The lunar mare are radioactively dated at:

A) 4.6 billion years old, forming first among the lunar features.
B) 4.2-3.9 billion years old, comparable to the adjacent highlands.
C) 3.9-3.2 billion years old, forming after most of the bombardment was over.
D) 3.5-2.5 billion years old, similar to the formation of our own oceans.
E) less than a billion years old, the most recent additions to the Moon.

LVPMS · **Reply #1 on:** Jul 27, 2018

Answer to Question 1

The conditions for feeding the active galaxy's black hole are greatly assisted by tidal interactions or even cannibalism; such collisions will be much more common in rich clusters, where the galaxies are much closer than normal.

Answer to Question 2

C