Nasa discovers a supermassive black hole that got kicked out of its galactic core by gravitational waves

Astronomers using the Hubble space telescope noticed something abnormal about a galaxy 8 billion light years away. There was a bright spot in the galaxy, a quasar, which is the glowing cloud of gas orbiting a supermassive black hole. Normally, the quasar is at the center of galaxies, the focal point of all the mass in a galaxy, known as the galactic core. However, the quasar is at a distance of 35,000 light years from where it should have been. Apparently, some monstrous forces kicked the supermassive black hole out of its place. [caption id=“attachment_368658” align=“aligncenter” width=“640”]  The brightest object in the picture is the quasar around the rogue supermassive black hole. This is light that is 8 billion years old. Image: Nasa.[/caption] The head researcher of the team that figured out what was happening, Marco Chiaberge says “I was anticipating seeing a lot of merging galaxies, and I was expecting to see messy host galaxies around the quasars, but I wasn’t really expecting to see a quasar that was clearly offset from the core of a regularly shaped galaxy. Black holes reside in the center of galaxies, so it’s unusual to see a quasar not in the center.” [caption id=“attachment_368659” align=“aligncenter” width=“640”]  A visual explanation of the sequence of events. Image: Nasa.[/caption] The supermassive black hole in question has the mass of one billion of our suns. To eject it from the center of the galaxy, would require the energy of 100 million supernovas. The researchers found evidence of a collision between two galaxies, which gave them a clue to what had happened. Apparently, when the two galaxies merged, the two supermassive black holes in their respective galactic cores also merged. As the two supermassive black holes got closer and closer together, the space around them rippled with gravitational waves. [caption id=“attachment_351422” align=“aligncenter” width=“640”]  Gravitational waves were first detected in the Ligo facility. Image: MIT/Ligo[/caption] If one of the two supermassive black holes was bigger, or if one was spinning much faster, then there would be a distrubance in the ripples. Once the two supermassive black holes merged into a single supermassive black hole, the gravitational waves created by the merger shot the black hole out of the galactic core like a rocket. If the interpretation is correct, then the finding adds to the evidence that it is possible for supermassive black holes to merge.

Gravitational waves were theorised to exist by Albert Einstein, who predicted that gravitational waves would be the result of a collision between two extremely massive objects. Gravitational waves were detected for the first time in 2016 at a Ligo facility, believed to originate from a distant collision of two black holes, and was the biggest physics story of the year . A Ligo facility is coming up in India as well, and may have a role to play in identifying other collisions between black holes.