For the first time ever, scientists have seen an unusual light signal that appears to be repeating itself from a distant quasar. And no, before the thought crosses your mind, this is not a sign of extraterrestrial life, but rather a signal from two black holes. These signals are an indication of two supermassive black holes that are in the last stages of merging together.
According to a new study published in the journal Nature, black hole mergers are critical steps in the formation and evolution of large galaxies. And the supermassive black holes found in their centers are also significant in regulating the creation of a star in a galaxy.
George Djorgovski, an astronomer at the California Institute of Technology in Pasadena, says that "these massive black holes are separated by distances ranging from light-years to several thousands of light years."
Black holes are actually impossible to see, but the accretion disk formed by the pull of surrounding gases form a swirling band of material, due to the strong gravitational pulls make them visible. These particles are accelerated to a very high speed, which generates a huge amount of energy in the form of heat, gamma rays and x-rays.
According to researchers, a black hole forms a quasar when it goes through this process, making it a highly illuminated object to such an extent that it's greater than all the stars present in its host galaxy. Researchers also believe that this discovery could give them clues about the "final parsec problem" -- a mystery that has been problematic in astrophysics for quite some time.
The lead author of the study Matthew Graham, who is a senior computational scientist, says that the final stages of the merger of the two supermassive black holes are not yet understood even to a decent level. The founding of such a system at this stage of merger gives astronomers an opportunity to look at what actually takes place in the process.
Black holes are the cold remnants of former stars that are so dense that no matter is able to escape their power gravitational pulls, including light. Over time, these black holes can absorb other stars or merge with other black holes to form supermassive black holes that could include millions of solar masses.
