Markarian 231 is the closest galaxy to the Milky Way to host a quasar — the bright cores of active galaxies capable of forming stars of their own. And NASA just discovered that that particular quasar, 600 million light years away, is actually the result of a pair of black holes furiously orbiting one another, locked in a cosmic romance not even Carl Sagan could have dreamed of.
As far as we’ve known, black holes almost always present themselves as solitary regions of literal suck, where matter are pulled in and unable to ever escape from. But scientists have always theorized that two black holes could become locked in a kind of gravitational dance where they exist in relative harmony. This is the first time humans have ever observed something like this actually happening.
NASA’s announcement explains that if there were only one black hole present at the quasar, “the whole accretion disk made of surrounding hot gas would glow in ultraviolet rays.”
“Instead, the ultraviolet glow of the dusty disk aburptly drops off toward the center. This provides observational evidence that the disk has a big donut hole encircling the central black hole. The best explanation for the donut hole in the disk…is that the center of the disk is carved out by the action of two black holes orbiting each other.”
You can see in the illustration above what that’s presumed to look like. The smaller of the two black holes orbits the inner edge of the accretion disk. NASA scientists think the findings could indicate that quasars with two central black holes are much more common than we think.
The origins of this serendipitous meeting seem to be when a small galaxy began colliding into Markarian 231, introducing its own black hole (worth four million solar masses!) to a black hole that had already parked itself in the neighborhood (weighing in at a more chubby 150 million solar masses).
The embrace resulted in a tremendous amount of matter being sucked in, and a tremendous amount of energy being released, accelerating star formation in the region.
But like all love stories, this one will eventually end in disaster. The two black holes will, at some point in the next few hundred thousand years, crash into one-another and end their dance in a violent burst of explosive bluster.