Researchers have spotted the first type II quasar, an object on the fringes of the known universe whose existence they had suspected for two decades. The finding is an important step forward in efforts to understand how black holes and galaxies formed in the early universe, according to astronomers at the Krieger School of Arts and Sciences at The Johns Hopkins University, the Space Telescope Science Institute, and the European Southern Observatory. Researchers anticipate that many more such quasars will soon be found through a special set of observational data that NASA is releasing to the general astronomy community this week.
Astronomers think both types of quasars are powered by massive black holes.
Unlike a type I quasar, though, a type II quasar is surrounded by or buried in an occluding cloud of gas and dust that reduces its brightness in visible light. The cloud, though, has little effect on X-ray radiation from the quasar. As the quasar matures, the extremely powerful radiation it emits disperses the shroud of gas and dust. We're very eager to get a sense of how prevalent they are, and to compare that to type I quasars. Astronomers first postulated the existence of type II quasars in the early 1980s, when they were beginning to agree on a unified model of quasars and other distant, bright objects thought to be powered by massive black holes.