Its brightness actually comes from two different sources. Light in the ultraviolet and optical range comes from what is known as an accretion disk surrounding a supermassive black hole. A supermassive black hole has millions of times the mass of the Sun. The second source of brightness, in the infrared portion of the spectrum, comes from thick dust heated by radiation from the center of the quasar. But in this quasar, about half comes from the accretion disk.
Quasars are some of the most energetic objects observed in the universe.
Each quasar generates more energy than the rest of a galaxy's stars combined. The quasar observation occurred by accident. The team was studying the Sagittarius Dwarf Galaxy's interaction with our own. They were observing stars in the halo of our galaxy when this very bright object showed up in one observation. The quasar is estimated to be 11 billion light years from Earth.