Astronomers identify possible renegade supermassive black hole

12 May 2017

Illustration of a black hole. Image: M Helfenbein/Yale University/OPAC

Astronomers have spotted something rather unusual: a supermassive black hole that appears to have gone rogue, drifting through space.

When astronomers look into deep space with their telescopes and spot a supermassive black hole, they can usually be assured that when they look back decades later, that same black hole will still be there.

However, a team of researchers using NASA’s Chandra X-ray Observatory has discovered one that is not only incredibly powerful, but appears to be moving.

This supermassive black hole is located in an elliptical galaxy about 3.9bn light years from Earth and contains approximately 160m times the mass of our sun.

Initial theories into how exactly the black hole began moving suggests it likely ‘recoiled’, a term used in astronomy when two smaller supermassive black holes collide and merge to form an even larger one.

During this time, the amount of energy made during a collision would create gravitational waves in one particular direction.

This newly formed black hole could have received a kick in the opposite direction of those waves, pushed out of its galaxy’s centre.

How it was found

In search of this recoiled black hole, astronomers sifted through reams of data from Chandra and optical data recorded during the Sloan Digital Sky Survey to find examples of two bright x-ray peaks in a galaxy’s centre.

This would suggest the presence of two supermassive black holes, or that a recoiling black hole moved away from the cluster of stars in the centre of the galaxy.

So, when this recent candidate was discovered, a supermassive black hole was located around 3,000 light years from the galaxy’s centre, while the second source shows a black hole with a velocity different from its host galaxy.

While this would suggest the existence of a recoiled model, another possibility is that two supermassive black holes are located in the centre of the galaxy, but one of them is not producing detectable radiation because it is growing too slowly.

Publishing its findings in the Astrophysical Journal, the research team will now conduct further research to prove that it recoiled, as part of an effort to understand its enigmatic properties.

Colm Gorey was a senior journalist with Silicon Republic