'Sideline Quasars' Team Up to Prevent Galaxy Formation: Secrets to Early Universe Revealed

Astronomers may be getting a better understanding about the early universe and how it formed. They've found that "sideline quasars" teamed up with one of the brightest quasars glowing in the universe 11 billion years ago in order to prevent small galaxy formation.

Quasars are the brightest and most distant objects in the universe. They're essentially very energetic and distant active galactic nuclei, galaxies that have "gone haywire" because of supermassive black holes that gorged themselves in the cores. They were first discovered about 50 years ago by Caltech astronomer Maarten Schmidt, who witnessed a quasar that was roughly 2 billion light-years from Earth and was approximately 40 times more luminous than an entire galaxy of 100 billion stars.

The researchers conducting this particular study used the Hubble Space Telescope in order to make their observations. The quasar they observed acted as a "lighthouse" for the observations and allows the scientists to better understand the conditions of the early universe. In particular, they studied the gaseous material between the telescope and the quasar. In order to probe this "fossil record" of gases, they employed COS, which breaks light into its individual components. This reveals information about the temperature, density, velocity, distance and chemical composition of galaxies, stars and gas clouds. 

About 11 billion years ago, blasts of ionizing radiation from black holes in the cores of quasars stripped electrons from primeval helium atoms. This initial ionization that charged the helium gas occurred shortly after the Big Bang. Through their observations, the researchers were able to tell that "sideline quasars," located out of the telescope's view, probably reionized intergalactic helium gas from different directions. This prevented the gas from gravitationally collapsing and forming new stars. Essentially, the quasars were preventing galaxies from forming.

"While there are likely hundreds of quasars in the universe, there are only a handful you can use for a study like this," said Michael Shull, one of the researchers, in a press release. "For our purposes, they are just a really bright background light that allows us to see the edge of the universe, like a headlight shining through fog."

The findings could have implications for how researchers view the early history of our universe. It could even reveal some of the history of the Milky Way.

"Our own Milky Way has a dormant black hole in its center," said Shull in a press release. "Who knows? Maybe our Milky Way used to be a quasar."

The details of the study are published in the Astrophysical Journal.