As two galaxies enter the last stages of merging they become locked in a gravitational orbit around each other, as a result, astronomers believe that the galaxies’ supermassive black holes at their center would inevitably collide and merge to become one.
In a new study, published last week in the Astrophysical Journal Letters, astronomers from the University of Maryland have detected a flashes of light from a quasar in deep space which may indicate the existence of black hole binaries.
We believe we have observed two supermassive black holes in closer proximity than ever before.
Said Suvi Gezari who is a co-author of the study.
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.
Typically, when black holes feast on surrounding matter, that matter is accelerated to very fast speeds and heated up to the point that it emits vast amounts of energy — powerful X-rays and gamma rays — which in turn produces the most extremely luminous object in the universe called quasars.
Scientists theorize that when two black holes orbit as a binary, that consumption of matter will be cyclical, as a result, the binary’s quasar would respond by brightened or dimming.
Using the Medium Deep Survey telescope in Hawaii, Dr Gezari and his colleagues looked for so-called variable quasars PSO J334.2028+01.4075 which has a very large black hole with about 10 billion solar masses and emitting a periodic flash of light repeating every 542 days.
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.
Said Tingting Liu, the paper’s first author.
Scientists plan to continue searching for new variable quasars, as larger and larger telescopes come online, researchers hope to find thousands of these merging supermassive black holes in the deep space.
These telescopes allow us to watch a movie of how these systems evolve.
What’s really cool is that we may be able to watch the orbital separation of these supermassive black holes get smaller and smaller until they merge.