Searching for Ancient Galaxies with a James Webb Telescope: “First Chapter of the Universe”

We expect galaxies to grow from small to large, and according to theory it’s quite gradual,” says researcher Ivo Labbé, an astronomer at Swinburne University of Technology in Australia. “It takes a while to collect 100 billion stars. collect.”

Baby systems

The idea was that if they looked at the early universe – “the nursery of the universe” – you would see very small baby galaxies. “What we have found is something completely different!” enthuses Labbé. “We’ve seen some very red, weird galaxies. It takes a lot of stars to generate that light. That means these galaxies are very massive. We’re seeing galaxies the same size as the Milky Way, which is already quite a big galaxy.”

Moreover, these “babies” are not as large as the Milky Way, but 30 times more compact. “Very strange and exciting,” says Labbé. “It undermines the models we normally use to explain the growth of stars and galaxies in the Universe.” According to the astronomer, galaxies are so large that the question is whether there is enough gas in the universe to form them. And then you come to the field of the big Bang theory. “It’s been around for 50 years and has been tested very well: you can’t just change that.”

First chapter

Researchers are in fact faced with many new questions. What follows is a long process: “We will make detailed images of these galaxies: then you will see exactly what is happening, but it will take another year. We are excited ! Then we’ll know exactly what the light is forming, whether it’s stars or whatever.”

You might wonder what it matters to know what the nursery of the universe looked like millions of years ago, but Labbé has an answer. “After the Big Bang, there were no stars or galaxies, plants or humans. The first galaxies and stars that formed eventually formed the particles of our bodies. This nursery is, in a sense, our own story. . It’s an origin story. , almost emotional in fact. The story of our own history, the first chapter of the universe.”