Orbital motion has finally been detected in a pair of supermassive black holes, concluding a study that has been over a decade in the making.
According to a report from the National Radio Astronomy Observatory, astronomers used the National Science Foundation's Very Long Baseline Array (VLBA) to detect the orbital motion of two supermassive black holes in the elliptical galaxy 0402+379 about 750 million light years away from Earth.
This pair of supermassive black holes boasts impressive size with a combined mass 15 billion times bigger than the sun. Another unique feature is their distance from each other - only about 24 light-years, which is a narrow gap for a system such as this one.
"This is the first pair of black holes to be seen as separate objects that are moving with respect to each other, and thus makes this the first black-hole 'visual binary,'" explained Greg Taylor of the University of New Mexico (UNM).
For the latest research, the scientists used VLBA data from 2009 and 2015 as well as re-analysis of previously collected information. From these observations, they were able to confirm motion, pointing to the two black holes orbiting each other. A single orbit is completed in roughly 30,000 years, according to their initial analysis.
Supermassive black holes - distinguished by its enormous size often billions times bigger than the sun - are known to be located at the cores of most galaxies. Galaxies with two are believed to have merged with another galaxy in the past, and the black holes may eventually follow in merging in the future. In fact, scientists such as UNM graduate student Karishma Bansal believe that this particular pair will fuse together millions of years from now.
"We need to continue observing this galaxy to improve our understanding of the orbit, and of the masses of the black holes," Taylor said. "This pair of black holes offers us our first chance to study how such systems interact."
The study was published in The Astrophysical Journal.