Researchers believe that when the two galaxies enter in the final stage of merging, the supermassive black holes form a binary, but there is no evidence to prove this theory.
In this phenomenon of binary black holes, black holes would be in such close orbit that they would be gravitationally bound to one another.
Gezari, assistant professor of astronomy at the University of Maryland, and coauthor of the study said, “We believe we have observed two supermassive black holes in closer proximity than ever before, this pair of black holes may be so close together that they are emitting gravitational waves, which were predicted by Einstein’s theory of general relativity.”
Black holes are surrounded by dust and matter which pulls all the materials because of its gravitational force, causing it to accelerate and emit electromagnetic energy, a flash of light called quasar.
When two black holes orbit as a binary they absorb matter cyclically, suggesting that they would periodically brighten and dim.
Panoramic Survey Telescope and Rapid Response System (Pan-STARRS1) Medium Deep Survey are used by the researchers to search the sky for these types of quasars.
The study led to the discovery of quasar PSO J334.2028+01.4075, which contains a black hole of 10 billion solar masses that emits a periodic optical signal that repeats every 542 days.
UMD astronomy graduate student Tingting Liu, the first author of the paper said, “The discovery of a compact binary candidate supermassive black hole system like PSO J334.2028+01.4075, which appears to be at such close orbital separation, adds to our limited knowledge of the end stages of the merger between supermassive black holes.”
The findings of the study are published in the journal Astrophysical Journal Letters.