NASA has captured images using several of the world's most powerful telescopes, which appear to show a supermassive black hole being ejected from its home galaxy at high speed.
The galaxy in question is CID-42, and lies a mere 4 billion light years from our own Milky Way galaxy. Using images taken from the Hubble Space Telescope, and the Canada-French-Hawaii Telescope, astronomers discovered the galaxy housed two large optical light sources and a large X-Ray source, typically the telltale sign of a supermassive black hole. What they couldn't determine was whether the two optical sources were both emitting X-Rays, or just one.
"The previous data told us that there was something special going on, but we couldn't tell if there were two black holes or just one," said Martin Elvis, an astronomer at the Harvard Smithsonian Center for Astrophysics. "We needed new X-ray data to separate the sources."
Supermassive black holes are thought to reside at the center of every galaxy, and it's hypothesized that some galaxies may contain two supermassive black holes which orbit around each other. In the event two black holes collide or merge, it is believed the resulting gravitational waves and center of gravity would add a kick velocity to the merged supermassive black hole that could result in it being thrown right out of the galaxy. This appears to be what has occurred at CID-42, though the merger is thought to have occurred as the resulting of colliding galaxies, as opposed to orbiting supermassive black holes.
Using X-Ray images from the Chandra Space Telescope, astronomers determined that the source of the X-Rays was travelling away from the other optical light source at speed of millions of miles per hour. The other light source is believed to be the star cluster that was left behind in the wake of the departing (and newly engorged) supermassive black hole.
While this event is considered to be extremely rare, it does raise the very likely possibility that there are several of these homeless supermassive black holes now roaming the universe.
The findings of this study will be published in the June 10 issue of the Astrophysical Journal.
