Tightest Trio of Supermassive Black Holes Discovered in Distant Galaxy

A team of international scientists has discovered a distant galaxy more than four billion light years away that consists of three closely orbiting super massive black holes.

In a collaborative effort, scientists from Oxford University and University of Cape Town identified the distant galaxy with super massive black holes after examining six systems that were selected as suitable candidates containing two supermassive black holes. This new finding will help astronomers hunt gravitational waves i.e. the ripples in spacetime, predicted by Einstein.

The discovery was made using European VLBI Network, an array of European, Chinese, Russian and South African antennas. They also used 305 meter Arecibo Observatory that is located in Puerto Rico.

The galaxy with the tightest trio of black holes was detected at a large distance in which two were seen orbiting each other ike the binary stars, clearly indicating that the closely-packed supermassive black holes are more common than previously thought.

Supermassive black holes, some of the powerful cosmic objects are known to hold the entire galaxy together. They are billion times the mass of the Sun. Mostly all galaxies are known to have one supermassive black hole at the center, but at times the galaxies that evolve through merging may contain more than one supermassive black hole.

Professor Matt Jarvis of Oxford University's Department of Physics, an author of the paper, said, "General Relativity predicts that merging black holes are sources of gravitational waves and in this work we have managed to spot three black holes packed about as tightly together as they could be before spiralling into each other and merging. The idea that we might be able to find more of these potential sources of gravitational waves is very encouraging as knowing where such signals should originate will help us try to detect these 'ripples' in spacetime as they warp the Universe."

The astronomers focused on a galaxy with alphabet soup name of SDSS J150243.09+1115573, which they assume is a candidate having a pair of supermassive black hole. This is located nearly 4.2 billion light years away from the Earth, according to Space.Com. They investigated the galaxy by merging signals from large radio antennas that is separated by 6,200 miles. This helped to view every detail 50 times more finer than was possible with Hubble's Space Telescope.

The scientists can measure the gravitational waves emitted from blackholes system as their orbits decrease using future radio telescopes like Square Kilometre Array (SKA).

Dr Roger Deane from the University of Cape Town said, "What remains extraordinary to me is that these black holes, which are at the very extreme of Einstein's Theory of General Relativity, are orbiting one another at 300 times the speed of sound on Earth. Not only that, but using the combined signals from radio telescopes on four continents we are able to observe this exotic system one third of the way across the Universe. It gives me great excitement as this is just scratching the surface of a long list of discoveries that will be made possible with the Square Kilometre Array (SKA)."