Quasars

A quasar is a supermassive black hole surrounded by an accretion disk. An accretion disk is a flat, disk-like structure of gas that spirals around a black hole, a new star, a white dwarf, etc. A quasar attracts this gas and sometimes other stars or small galaxies with their superstrong gravity, sucking them into the black hole. When a galaxy, star or gas is absorbed into a quasar, a massive collision of matter occurs that causes an explosive output of radiation energy and light. This great burst of energy results in a flare, a distinct characteristic of quasars. Because of these collisions, quasars are believed to be the brightest objects in the universe.

The jet of light being emitted by the quasar is the flare.