Astronomers used to assume galaxies formed first and slowly grew the black holes at their centres. But JWST is now finding objects in the early universe where the black hole appears to have arrived first — already enormous before a full galaxy had grown around it.

The old classroom version of galaxy formation had an appealing order to it. First came the galaxy: gas cooled, stars formed, structure assembled. Then the black hole at the centre grew with it. JWST has made that sequence harder to treat as the default story for the early universe. In several objects seen within the [...] The post Astronomers used to assume galaxies formed first and slowly grew the black holes at their centres. But JWST is now finding objects in the early universe where the blac