A Quasar - Galaxy Collision?
In 1963 astronomers were astounded to discover that certain faint, star-like objects have very large redshifts. The large redshifts imply that these objects, now known as quasars (QUASi-stellAR objects), lie near the edge of the observable Universe. To be visible at such extreme distances of billions of light years, they must emit tremendous amounts of energy. Where does the energy come from? In the most widely accepted model, a quasar is the bright nucleus of an active galaxy powered by a central, supermassive black hole.