Which came first: black holes or galaxies?

A new analysis of James Webb Space Telescope data shows that black holes not only existed at the beginning of time, they gave birth to new stars and created supercharged galaxies.

This insight overturns theories about how black holes shape the universe, and challenges the classical understanding that they were formed after the first stars and galaxies emerged. Instead, black holes may have dramatically accelerated the birth of new stars during the universe's first 50 million years, a fleeting period within its 13.8 billion-year history.

“We know that these monstrous black holes exist at the centers of galaxies near our Milky Way, but the big surprise now is that they were also present at the beginning of the universe and were almost like the building blocks or seeds for the earliest galaxies.” Lead author Joseph Silk is a professor in the Department of Physics and Astronomy at Johns Hopkins University and the Institute of Astrophysics, Sorbonne University, Paris. “They really boosted everything, like the giant amplifier of star formation, which is a complete paradigm shift of what we previously thought possible – so much so that it could completely shake up our understanding of how galaxies form. “

work recently published Astrophysical Journal Letters,

Distant galaxies from the early universe seen through the Webb telescope appear much brighter than scientists had predicted and reveal unusually high numbers of young stars and supermassive black holes, Silk said.

Conventional wisdom holds that black holes formed after supergiant stars collapsed and that galaxies formed after the first stars lit up the dark early universe. But Silk's team's analysis shows that black holes and galaxies coexisted and influenced each other's fate during the first 100 million years. If the entire history of the universe were a 12-month calendar, Silk said, those years would be like the first days of January.

“We are arguing that the black hole expels crushed gas clouds, causing them to become stars and significantly accelerating the rate of star formation,” Silk said. “Otherwise, it is very hard to understand where these bright galaxies came from because in the early universe they were generally small. Why on Earth should they form stars so rapidly?”

Black holes are regions in space where gravity is so strong that nothing can escape their pull, not even light. Because of this force, they generate powerful magnetic fields that create violent storms, expel turbulent plasma and ultimately act like giant particle accelerators, Silk said. This process is likely why Webb's detectors have seen more of these black holes and bright galaxies than scientists expected, he said.

“We can't see these violent winds or jets very far away, but we know they must exist because we see many black holes early in the universe,” Silk said. “These fierce winds from the black hole crush nearby gas clouds and turn them into stars. This is the missing link that explains why these first galaxies are so much brighter than we expected.”

Silk's team predicts that the young universe will have two phases. During the first phase, high-speed outflow from the black hole accelerated star formation, and then, in the second phase, the outflow slowed. A few hundred million years after the Big Bang, supermassive black hole magnetic storms caused clouds of gas to collapse and new stars were born at a rate far greater than that seen billions of years later in normal galaxies, Silk said. Star formation slowed as these powerful outflows transitioned into a state of energy conservation, he said, reducing the gas available for galaxies to form stars.

“We thought that in the beginning, galaxies formed when a giant gas cloud collapsed,” Silk said. “The big surprise is that there was a seed in the middle of that cloud – a big black hole – and that helped the interior of that cloud turn into stars at a much faster rate than we expected. And that's how the first galaxies appeared. Are bright in appearance.”

The team hopes that future Webb telescope observations, along with more accurate counts of stars and supermassive black holes in the early universe, will help confirm their calculations. Silk hopes that these observations will also help scientists gather more clues about the evolution of the universe.

“The big question is, what was our beginning? The Sun is one star out of 100 billion in the Milky Way galaxy, and there is also a massive black hole sitting in the middle. What is the relationship between the two?” He said. “Within a year we will have much better data, and many of our questions will begin to be answered.”

The authors include Colin Norman and Rosemary FG Wyse of Johns Hopkins; Michelle C. Begelman of the University of Colorado and the National Institute of Standards and Technology; and Adi Nusser of the Israel Institute of Technology.