Scientists have identified a massive black hole in the early universe that grew way faster than its host galaxy.
The discovery runs counter to most observations about black holes, which are massive areas of space with extraordinarily strong gravity that can pull in anything — even light. In most cases, black holes and their host galaxies expand at the same rate.
This particular black hole formed in the early universe, roughly two billion years after the Big Bang. An international research group, including astronomers from Yale University, ETH Zurich, the Max-Planck Institute in Germany, Harvard University, the University of Hawaii, INAF-Osservatorio Astronomico di Roma, and Oxford University, made the discovery during a project to map the growth of supermassive black holes across cosmic time.
This particular black hole, located in the galaxy CID-947, is among the most massive black holes ever found. It measures nearly 7 billion solar masses (a solar mass is equivalent to the mass of our Sun).
Lead author Benny Trakhtenbrot said that it was the mass of the surrounding galaxy that surprised the research team most. The measurements correspond to the mass of a typical galaxy.
Most galaxies, including our own Milky Way, have a black hole at their center, holding millions to billions of solar masses. Not only does the new study challenge previous notions about the way host galaxies grow in relation to black holes, it also challenges earlier suggestions that the radiation emitted by expanding black holes curtails the creation of stars.
Stars were still forming in CID-947, the researchers said, and the galaxy could continue to grow. They said CID-947 could be a precursor of the most extreme, massive systems observed in today’s local universe, such as the galaxy NGC 1277 in the Perseus constellation, 220 million light-years from the Milky Way. But if so, they said, the growth of the black hole still greatly anticipated the growth of the surrounding galaxy, contrary to what astronomers thought previously.
