A team of researchers from Purdue University and other institutions has discovered a supermassive black hole binary system, one of only two known such systems. The two black holes, which orbit each other, likely weigh the equivalent of 100 million suns each. One of the black holes powers a massive jet that moves outward at nearly the speed of light. The system is so far away that the visible light seen from Earth today was emitted 8.8 billion years ago.
The two are only between 200 AU and 2,000 AU apart, at least 10 times closer than the only other known supermassive binary black hole system. One AU is the distance from the Earth to the sun, which is about 150 million kilometers (93 million miles) or 8.3 light minutes.
The close separation is significant because such systems are expected to merge eventually. That event will release a massive amount of energy in the form of gravitational waves, causing ripples in space in every direction (and oscillations in matter) as the waves pass through.
Finding systems like this is also important for understanding the processes by which galaxies formed and how they ended up with massive black holes at their centers.