Question

How does a galaxy that contains a quasar different from an ordinary galaxy?

Answer 1

A quasar is simply an active supermassive black hole and radiates a lot more energy than a supermassive black hole in an ordinary galaxy

Explanation:

As the quasar is an ACTIVE supermassive black hole, it takes in much more matter and thus is much brighter than a supermassive black hole in an ordinary galaxy. The quasar is massive and gives out energy, mostly in x-rays. As a consequence, a galaxy that contains a quasar is MUCH MORE brighter than a galaxy without one.