As if black holes weren't already scary enough, it now appears that they can move — and they can move fast. New observations from NASA's Chandra X-ray Observatory have revealed a massive black hole that is careening away from its host galaxy at a speed of several million miles per hour. Astronomers speculate that the black hole collided and merged with another black hole and received a powerful recoil kick from the gravitational wave radiation. The finding suggests that large black holes may be roaming undetected out in the vastness of space.
The research team, which was led by Francesca Civano of the Harvard-Smithsonian Center for Astrophysics (CfA), was surprised to discover that a supermassive black hole weighing millions of times the mass of the sun could be moved at all, let alone at enormous speeds. It is thought that gravitational waves, which are ripples in the fabric of space predicted by Albert Einstein, can exert an extremely power force under the right conditions.
Their results will appear in the June 10 issue of The Astrophysical Journal.
Civano's team were studying a system known as CID-42, located in the middle of a galaxy about 4 billion light years away. By using NASA's Hubble Space Telescope, they had previously spotted two distinct, compact sources of optical light in CID-42. But new optical data from ground-based telescopes in Chile supplied a spectrum that indicated the two sources in CID-42 were moving apart at an astounding 3 million miles per hour.
Based on the new evidence, the research team concluded that two galaxies must have collided, and that the supermassive black holes in the center of each galaxy also collided. In turn, the two black holes merged to form a single black hole that recoiled from the gravitational waves caused by the interstellar collision. It was the force of this collision that provided enough force to kick the black hole right out of the galaxy itself.
This theory is consistent with the results of computer simulations running similar scenarios.
As for the black hole itself, it is currently traveling through the depths of space in between galaxies, remaining largely invisible to us as it has consumed all of the gas which surrounded it when it was thrown out of its host galaxy.
Via. Top image via NASA. Body image via X-ray: NASA/CXC/SAO/F.Civano et al; Optical: NASA/STScI; Optical (wide field): CFHT, NASA/STScI.