Two “supermassive” black holes about a few hundredths of a light-year apart, could merge in around one million years time. An event like this has never been observed before.
Iflscience.com reports:
The supermassive black holes at the center of most large galaxies (including ours) appear to co-evolve with their host galaxies: As galaxies merge, their black holes grow more massive too. Since we can’t actually see black holes, researchers look for their surrounding bands of material called accretion disks, which are produced by the intense pull of the black hole’s gravity. The disks of supermassive black holes can release vast amounts of heat, X-rays, and gamma rays that result in a quasar—one of the most luminous objects in the universe.
“The end stages of the merger of these supermassive black hole systems are very poorly understood,” Graham says. “The discovery of a system that seems to be at this late stage of its evolution means we now have an observational handle on what is going on.”
Study co-author Daniel Stern of JPL adds: “The black holes in PG 1302-102 are, at most, a few hundredths of a light-year apart and could merge in about a million years or less.” And when that happens, The New York Times reports, it’ll release as much energy as 100 million supernova explosions.
