How did supermassive black holes form? What is dark matter? In an alternative model for how the Universe came to be, as compared to the ‘textbook’ history of the Universe, a team of astronomers propose that both of these cosmic mysteries could be explained by so-called ‘primordial black holes’.
If most of the black holes formed immediately after the Big Bang, they could have started merging in the early Universe, forming more and more massive black holes over time.
According to this model, the Universe would be filled with black holes all over. Stars would start to form around these clumps of ‘dark matter’, creating solar systems and galaxies over billions of years. If the first stars indeed formed around primordial black holes, they would exist earlier in the Universe than is expected by the ‘standard’ model. Primordial black holes could then be the seeds from which all black holes form, including the one at the centre of our own Milky Way galaxy.
ESA’s future missions Webb, Euclid and LISA mission may be able to shed light on the mystery.
In the graphic, the focus is on comparing the timing of the appearance of the first black holes and stars, and is not meant to imply there are no black holes considered in the standard model.