Scientists spot two quasars in merging galaxies light-years away

Scientists have spotted pairs of quasars — supermassive black holes feeding on huge amounts of material — in merging galaxies light-years from our own.

Why it matters: By learning more about these types of rare mergers, scientists may be able to piece together details about how galaxies grow and evolve over billions of years.

• “In spite of their rarity, they represent an important stage in the evolution of galaxies, where the central giant is awakened, gaining mass, and potentially impacting the growth of its host galaxy,” Shenli Tang, an author of the study about these quasar pairs, said in a statement.

What they did: The team used three telescopes atop Maunakea in Hawaii to identify three quasar pairs in distant merging galaxies after hunting through thousands of previously identified quasars in a database.

• Astronomers previously identified quasar pairs, but simulations predicted far more than what's been observed in part because these objects are difficult to see. (Both quasars shine brightly due to the gas heating up around the feeding black hole and can be hard to distinguish from one another.)
• The new discoveries of these quasar pairs — detailed in a study in The Astrophysical Journal — suggest about 0.3% of all quasars are actually these dual quasar pairs.