NASA telescopes detect closest confirmed pair of supermassive black holes: ‘Like two Sumo wrestlers squaring off…’

NASA observed the closest confirmed pair of supermassive black holes this week within the gas-rich galaxy MCG-03-34-64. The duo — described rather poetically as ‘two Sumo wrestlers squaring off’ — was found through multiwavelength (visible and X-ray light) observations using the Hubble Space Telescope and Chandra X-ray Observatory. They are buried deep within a pair of colliding galaxies and located approximately 300 light-years apart.

A black hole is a massive concentration of matter packed into a tiny space — so dense that gravity just beneath its surface does not permit anything (including light) to escape. Black holes can be surrounded by rings of gas and dust, called accretion disks that emit light across many wavelengths — including X-rays.

The twin black holes (whose discovery was published this week in The Astrophysical Journal) are fueled by infalling gas and dust — causing them to shine brightly as active galactic nuclei. 

According to a NASA update, AGN binaries like this were likely more common in the early universe when galaxy mergers were more frequent.

“Hubble's high-resolution imaging revealed three optical diffraction spikes nested inside the host galaxy, indicating a large concentration of glowing oxygen gas within a very small area,” explained a NASA press release.

Astronomers have so far observed one pair of binary black holes in even closer proximity than in MCG-03-34-64 by using radio telescopes. However this is yet to be confirmed by other wavelengths.

"We were not expecting to see something like this. This view is not a common occurrence in the nearby universe, and told us there's something else going on inside the galaxy. When we looked at MCG-03-34-64 in the X-ray band, we saw two separated, powerful sources of high-energy emission coincident with the bright optical points of light seen with Hubble. We put these pieces together and concluded that we were likely looking at two closely spaced supermassive black holes," said lead study author Anna Trindade Falcão.