When a dying star collapses inward into an infinitely small point under the pressure of its own weight, it forms a black hole. The gravitational field of black holes are so powerful that even light cannot escape its pull. Black holes that have masses more than millions or billions of suns come under the category of supermassive black holes. One supermassive black hole is present at the centre of every galaxy. Sagittarius A*, 26,000 light years away, is the black hole at the centre of Milky Way.
A supermassive black hole at the centre of the galaxy cluster Abell 2261 has been missing, according to reports in January 2021. Attempts have been made to locate the missing black hole with the help of NASA’s Chandra X-ray Observatory and Hubble Space Telescope, but it has not been located.
Abell 2261 is about 2.7 billion light years away from Earth. With the help of the data collected in 1999 and 2004, scientists have attempted to find the black hole at the centre of this galaxy cluster but it could not be found. In 2018, a team of Scientists from the University of Michigan suggested that the ‘missing’ black hole might be due to the merging of two small galaxies to form Abell. In the process, two black holes could have also merged and formed one big black hole. During such a merging.
Gravitational waves are released that squeeze and stretch everything in their way. The new black hole can be pushed into the opposite direction creating a recoiling black hole. This happens when the number of gravitational waves sent in one direction is stronger than the other. It has been assumed that the missing black hole could be floating about in space.
It has been established that smaller black holes can merge from such a process. However, there is no conclusive evidence to prove that supermassive black holes can merge to create recoiling black holes. This theory, if confirmed, could prove to be a major headway in the field of astronomy.