These billion - solar - mass monsters, residing in the centers of large galaxies, can glom together during galactic collisions after a spiraling dance, as shown here. (discovermagazine.com)
Other astronomers had found that the object, located 4.3 billion light - years from Earth, possessed two supermassive black holes, each the center of a large galaxy smashing into another. (sciencemag.org)
Astronomers have seen them shooting out of young stars just being formed, X-ray binary stars and even the supermassive black holes at the centers of large galaxies. (sciencedaily.com)