Why are there no nearby, or in other words, young quasars?

1 Answer
Dec 16, 2015

There are no nearby young quasars because the nearby galaxies are too old!


A quasar is a galaxy with a central black hole which has an accretion disc - a disc of matter spiralling into the black hole. The massive energy output of a quasar is due to matter falling into the accretion disc and being heated by gravitational effects of the black hole and from friction.

Most quasars are young galaxies for the result of the collision of galaxies. Our Milky Way galaxy was probably quasar in its youth! The quasars we see are in young galaxies which are so distant that their light has taken billions of year to reach us.