black-hole-binary-quasarA mysterious light signal from a faraway galaxy could point to two supermassive black holes finishing up a merger in the galaxy’s core, new research reveals. Scientists saw repeating pulses from a quasar — a bright galactic core powered by at least one huge black hole — and say the light is likely being generated during the latter stages of a monster black hole collision. If this interpretation is correct, researchers could learn a great deal more about the final phases of such mergers, where simulations tend to break down — a situation dubbed “the final parsec problem.” More