How did supermassive black hole at center of distant galaxy mysteriously disappear? Astronomers left perplexed
Astronomers were left perplexed after a supermassive black hole – which weighed up to 100 billion times the mass the of Sun – seemingly went missing. Scientists have been trying to locate the black hole using NASA’s Chandra X-ray Observatory and Hubble Space Telescope, but have so far found no evidence of its existence, the Indian Express reported.
Several space observers and enthusiasts on social media have since expressed confusion about the black hole's whereabouts, which was previously located at the center of a far-off galaxy. According to the report, the celestial giant was supposed to be found in Abell 2261, an enormous galaxy cluster located about 2.7 billion light-years away from Earth.
According to NASA, every sizeable galaxy has a supermassive black hole at its core, whose mass could be millions or even billions of times more than the Sun. Sagittarius A, the black hole at the center of our galaxy – the Milky Way – is reportedly 26,000 light-years away from our planet. Researchers have been using data gathered in 1999 and 2004 to pinpoint the center of the Abell galaxy, but have so far been unsuccessful in locating its black hole. According to a team at the University of Michigan, a reason for this could be that Abell's black hole "has been ejected from the center of the galaxy."
This may have happened owing to the merging of two smaller galaxies to form Abell, with their respective black holes merging to form an even bigger black hole, according to scientists who based their reasoning on 2018 data obtained from NASA’s Chandra Observatory.
When two black holes combine, they release intense waves of energy called gravitational waves. These are invisible ripples traveling at the speed of light, squeezing and stretching anything in their way, according to the Indian Express. "As per the theory of gravitational waves, during such a merger, when the amount of waves generated in one direction is stronger than another, the new big black hole can be sent away from the center of the galaxy into the opposite direction," the newspaper stated, adding that this was known as a "recoiling" black hole.
A study about recoiling black holes was conducted by a team lead by Dr. Kayhan Gultekin from the University of Michigan. It was later published in the American Astronomical Society journal.
Gultekin had reportedly been studying galaxy A2261-BCG when he noticed signs that the black hole had gone missing. “I was very skeptical and thought we would see something at the very center. But that turned out not to be the case," he told Motherboard, per the New York Post.
The team also noted that it would be hard to detect a recoiling black hole, considering it could be hiding anywhere in the galaxy.
That said, scientists are yet to establish definitive evidence for recoiling black holes when supermassive black holes merge and release gravitation waves. As of today, researchers have been able to verify only mergers of considerably smaller black holes. However, if the hypothesis published by Michigan researchers is proven to be true, it would mark a major breakthrough in the world of astronomy, the Indian Express reported.