Top: A gas-rich galaxy collides with a giant galaxy, producing a quasar. Credit: Computer simulation by Joshua Barnes, University of Hawaii. Bottom: Artist’s conception of the heart of a quasar, a massive black hole that sucks in a vortex of gas. Hawaii astronomers found that quasars shine because a giant galaxy with a large black hole collides with a gas-rich galaxy that feeds the black hole. Credit: A. Simonnet, Sonoma State University, NASA
