After introducing galaxies of various shapes, their
clustering, and the large-scale structure as observed by mankind to date,
we are close to conspiring a story of the universe as
a whole. That is what cosmologists are supposed to do.
Before providing more materials to do that, we shall take one more look at some galaxies which are very active in terms of power and variability.
16-01 Seyfert Galaxies and Radio Galaxies
16-03 Active Galactic Nuclei (AGN)