Webb revealed an unexpected twist in the history of the formation of black holes and galaxies

Webb revealed an unexpected twist in the history of the formation of black holes and galaxies

Illustration of a supermassive black hole in the early universe.

The first stages of the development of the universe are reminiscent of the age-old debate about which came first – the chicken or the egg. Did stars and galaxies form first, and then black holes slowly formed in between? Did black holes appear before the first galaxies?

As matter began to cool and condense after the Big Bang, it formed into the shapes and objects we’ve seen for most of our 13.8 billion-year history. Today, we see these objects as stars, united in gravitationally bound systems that we call galaxies. And at the center of almost every galaxy is a supermassive black hole.

It is traditionally believed that stars and galaxies appeared first. However, a new analysis of data on the early universe collected by the James Webb Space Telescope suggests that black holes and galaxies did in fact originate together – and that the black holes formed the galaxies that developed around them.

Supermassive black holes are a particular problem because some black holes are formed from stars. When a particularly large star dies, its core collapses and a black hole appears.

The largest black holes can form as a result of collisions between these objects… but supermassive black holes are millions and billions of times the mass of the Sun. If these objects are formed from scratch, it would take a very long time, and for such a scenario, stars would have to appear first.

Webb’s observations indicate that supermassive black holes appeared already at the dawn of the universe. We observed supermassive black holes 500 million years after the Big Bang, one after 470 million years, another after 400 million; and, interestingly, the mass of the last black hole, about 1.6 million Suns, turns out to be equal to the mass of the small galaxies orbiting it.

This suggests another mechanism for the formation of black holes: huge clouds of matter collapsed directly into black holes without becoming stars. According to the analysis conducted by Silk and her team, it is that they could have existed from the beginning, evolving with the small galaxy and stimulating its growth. When the central part of the cloud turned into a black hole, the outskirts of the cloud that remained became the material for the formation of new stars. The study was published in The Astrophysical Journal Letters.

In the process of feeding a black hole, powerful winds and jets of high-speed plasma arise, which penetrate the surrounding space, compressing the star-forming gas located in it and causing intense waves of star formation.

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