Artist's concept of a galaxy with a brilliant quasar – an active supermassive black hole millions to billions of times the mass of the sun – at its center. Among the brightest objects in the universe, quasars feed on infalling matter and unleash torrents of winds and radiation, shaping the galaxies in which they reside. Credit: NASA, ESA, Joseph Olmsted (STScI) Powerful radiation from active supermassive black holes, which are believed to sit at the center of most galaxies, can do more than