Scientists have just determined the formation processes of some of the oldest galaxies in the Universe during the turbulent period of the Cosmic Dawn. JWST’s observations of the early universe from about 13.3 to 13.4 billion years ago (just a few hundred million years after the Big Bang) revealed bright signatures of gas reservoirs actively entering three newly formed and growing galaxies.

“We can say that these are the first ‘direct’ images of galaxy formation we have ever seen,” says Kasper Elm Heinz, an astrophysicist at the Niels Bohr Institute in Denmark who led the research.

“During [космічний телескоп Джеймса Вебба] “Whereas we have previously been shown early galaxies in late stages of evolution, here we observe their birth and thus the formation of the first star systems in the universe.”

Known as the Cosmic Dawn, the first billion years after the Big Bang are shrouded in two things: mystery and the haze of neutral hydrogen that permeates the universe and prevents light from propagating freely. The first is actually a natural and direct consequence of the second, because light is the tool we use to understand the universe.

JWST is specifically designed to penetrate this haze, as the infrared wavelengths at which it observes space penetrate more easily and travel farther than other wavelengths. What we want to know is how it all comes together; It is how the first stars and galaxies emerged from the soup of hot primordial plasma, how the fog cleared in the light of the first objects, and how the universe took baby steps towards its present state.

Heinz and his international team used JWST’s powerful infrared eye to take a closer look at Cosmic Dawn, where they detected a signal traceable to up to three galaxies. Specifically, the signal came from the neutral hydrogen surrounding the galaxies as the gas absorbs and re-emits light from them.

Researchers found that these galaxies came into existence approximately 400-600 million years after the Big Bang, which occurred approximately 13.8 billion years ago. This makes these three galaxies among the earliest discovered galaxies.

“These galaxies look like bright islands in a sea of ​​neutral, opaque gas,” says Heinz.

Additionally, the researchers were able to distinguish gas reservoirs around galaxies from neutral intergalactic gas. These reservoirs have been determined to be quite large and occupy a fairly large portion of each galaxy; This suggests that they are actively creating galactic material. And the abundance of this gas also suggests that galaxies had not yet formed most of their stars at the time of observations.

“Within a few hundred million years after the Big Bang, the first stars formed before stars and gas began to coalesce into galaxies,” says Darach Watson, a cosmologist and astrophysicist at the Niels Bohr Institute. “This is a process that we can see starting in our observations.”

We still have many questions about Cosmic Dawn. We have barely scratched the surface and there are still many secrets wrapped up in neutral hydrogen, many of which have yet to be discovered. But the three galaxies discovered by Heinz and his team are one step ahead. Now that we know galaxies are there, we can take a closer look at them to better understand the galaxy formation process.

“One of the most fundamental questions we humans always ask is ‘Where do we come from?'” says astronomer Gabriel Brammer of the Niels Bohr Institute.

“Here, we piece together a little more of the answer, shedding light on the creation of some of the earliest structures of the universe. We will continue to explore this process until we can hopefully put more pieces together and solve the puzzles together.”