Supermassive black holes engaged in cosmic dance in nearest galactic neighbour

28 Aug 2015

An illustration of the binary black hole quasar in Mrk 231. Image via NASA, ESA, and G. Bacon (STScI)

NASA’s Hubble Space Telescope has spotted that in our nearest neighbouring galaxy that features a quasar, two supermassive black holes are engaged in a violent, cosmic dance with each other.

While spotting supermassive black holes is always a major achievement for astronomers, capturing two in close proximity to one another, but also feeding off one another in a cosmic dance, is really quite amazing.

The two black holes are located within the galaxy’s quasar – the powerful core of galaxies – and are believed to have fallen into orbit with one another following the merger of two smaller galaxies.

Designated Mrk 231, the galaxy was spotted by astronomers who spotted that the binary black holes left an empty, mysterious centre at its core, which would not be found on a typical singular black hole quasar.

This ‘donut hole’, the astronomers said, is believed to be effectively carved out by the duelling actions of the two black holes, with the second, smaller black hole orbiting the inner edge of the accretion, thus creating its own mini-disk with an ultraviolet glow.

Eventual cosmic collision

Located 600m light years away from Earth, the central black hole of Mrk 231 is estimated to be around 150m times the mass of our own sun, while its smaller companion is 4m times heavier than the sun.

Within just a few hundred thousand years, the astronomer team predict, the two black holes will eventually run into one another, creating a gargantuan black hole.

Publishing its findings in The Astrophysical Journal, the team of astronomers said this is a major breakthrough in black hole research.

“We are extremely excited about this finding because it not only shows the existence of a close binary black hole in Mrk 231, but also paves a new way to systematically search binary black holes via the nature of their ultraviolet light emission,” said Youjun Lu of the National Astronomical Observatories of China, Chinese Academy of Sciences.

As the late Leonard Nimoy said in The Simpsons, “The cosmic ballet goes on”.

Colm Gorey was a senior journalist with Silicon Republic