Astronomers have confirmed the mysterious “disappearance” of a supermassive black hole in the galaxy Abell 2261, located 2.7 billion light-years from Earth. It is assumed that in the center of Abell 2261 there should be a black hole with a mass of 3-100 billion Suns, but it has not yet been discovered. This is reported in the preprint of the article, published in the arxiv.org repository.
Scientists originally used the Chandra space X-ray observatory to look for signs of superheated matter falling into a giant black hole and emitting X-rays, but nothing of the kind was found. In the new work, experts analyzed even more data, and also considered the option in which a black hole could be ejected from the host galaxy as a result of the merger of the latter with another galaxy. In this case, two black holes should have merged into one even more massive black hole, which would have generated a gravitational wave.
Researchers have noticed indirect signs of the merger of two supermassive black holes. First, the core of Abell 2261 is much larger than expected for a galaxy of its size. Second, the distance between the center of the galaxy and the nearest dense cluster of stars is about two thousand light-years, which is quite a distance. This happens when two converging black holes begin to repel nearby stars.
However, neither the new data from Chandra nor the results of observations with the Hubble Space Telescope have shown signs of the existence of the black hole itself. This can be explained by the fact that the black hole either absorbs matter too slowly, remaining invisible to astronomers, or it managed to “run away” quite far from the center of the galaxy.