Scientists have discovered a rare medium-mass black hole (IMBH), 10 million light-years distant from Earth. The discovery of this exotic object will help uncover the mechanisms of formation of supermassive black holes, which are still unknown. This is reported in an article published in the Monthly Notices of the Royal Astronomical Society.
An unusual black hole is located in the Ghost of Mirach galaxy (NGC 404), so named because of the weak light and the close apparent location on the celestial sphere to the star Mirakh. The mass of the object is 550 thousand times the mass of the Sun. IMBHs occupy an intermediate position between stellar mass black holes (up to one hundred solar masses) and supermassive black holes or SMBHs (from a million to a billion solar masses). An ordinary black hole is formed by the collapse of a large star, but if the mass of the star is too large (130-250 solar masses), then it ends its life in the form of a pair-unstable supernova, which does not leave behind any residual object.
According to one model, rather large black holes are formed when a large amount of matter is absorbed, but the problem is that IMBHs are quite rare. According to another scenario, supermassive black holes arise from the direct collapse of dense interstellar clouds in the cores of galaxies. This is also indicated by the fact that SMBHs are found in the early Universe, when too little time has passed since the Big Bang for a black hole to grow to a huge size.
Researchers have discovered a black hole in Mirach's Ghost by observing the movement of gas around its core with the Atacama Large Millimeter Array (ALMA) radio telescope complex in Chile. The simulation results showed that the picture corresponds to the presence of a medium-mass black hole. According to the findings of scientists, its existence supports both models of SMBH evolution. It has a mass within the range predicted by direct collapse models, but actively absorbs interstellar gas.