WASHINGTON — The universe is one big dance party for black holes. New observations from the W.M. Keck Observatory in Hawaii and the Hubble Space Telescope found 33 merged galaxies in which pairs of supermassive black holes are “waltzing” around the galactic centers.
“Our result shows that such waltzing black holes are much more common than we previously knew,” said Julie Comerford of the University of California, Berkeley. Comerford presented her results on January 4 at the winter meeting of the American Astronomical Society.
Finding pairs of black holes moving in a certain way can help estimate how often galaxy mergers occur in the universe. Observations have shown that nearly every galaxy has a supermassive black hole — a black hole with a mass of a million to a few billion times that of the sun — at its center and that galaxies often collide and merge to create larger galaxies. Astronomers have expected to find many mid-merge galaxies by focusing on the two supermassive black holes, which should be orbiting each other in the middle. But so far, the dance floor has pretty much been empty.