Jacinta Bowler
A new theory is emerging in astronomy to explain the rapid formation of early stars with some saying they’ve answered the question of why so many stars formed quickly at the birth of the universe.
And it shakes up theories about what came first – black holes, or stars?
A new study, published in the Astrophysical Journal Letters has questioned scientists’ estimates of when the first supermassive black holes formed. The prevailing view has been that they formed after the first stars and galaxies, but the new research shows the ancient universe doesn’t work without the black holes being there at the same time.
“We know these monster black holes exist at the centre of galaxies near our Milky Way, but the big surprise now is that they were present at the beginning of the universe,” says Joseph Silk, astronomy professor at Johns Hopkins University and Sorbonne University.
Silk describes them as “like building blocks or seeds for early galaxies.”
“They really boosted everything, like gigantic amplifiers of star formation, which is a whole turnaround of what we thought possible before – so much so that this could completely shake up our understanding of how galaxies form.”
The researchers used the James Webb Space Telescope (JWST) to look at how ancient galaxies form. These ancient – and distant – galaxies looked brighter, and supermassive black holes seem to be there, even in the farthest and oldest reaches of the universe JWST can reach.
To make a supermassive black hole, you first need a really massive star. The story until now has been that the first stars were there first, with black holes only forming later.
But the JWST is seeing too many black holes and stars for that to make sense. The research suggests that the black holes and galaxies needed to exist together in order to form enough stars.
“We’re arguing that black hole outflows crushed gas clouds, turning them into stars and greatly accelerating the rate of star formation,” Silk said.
“Otherwise, it’s very hard to understand where these bright galaxies came from because they’re typically smaller in the early universe. Why on earth should they be making stars so rapidly?”
But there are still questions – the team need to confirm their calculations, and, find out more about how the early Universe got the point of having these stars and black holes in the first place.
“The big question is, what were our beginnings? The sun is one star in 100 billion in the Milky Way galaxy, and there’s a massive black hole sitting in the middle, too. What’s the connection between the two?” said Silk.
“Within a year we’ll have so much better data, and a lot of our questions will begin to get answers.”