Supermassive black hole rocketing out of distant galaxy at 5 million mph

The Bad Astronomer writes: Astronomers have found a supermassive black hole barreling out of its home galaxy at 5 million mph. The 3 billion solar mass behemoth formed from the merger of two slightly smaller black holes after two galaxies collided and themselves merged. The resulting blast of gravitational waves is thought to have been asymmetric, causing a rocket effect which launched the resulting black hole away. It's currently 40,000 light years from the galaxy's core.