James Webb space telescope uncovers galaxy's bright gas mystery

Using the James Webb Space Telescope, astronomers have observed a galaxy in the young universe whose gas emits more light than its stars. This remarkable phenomenon, as scientists emphasise, provides valuable information about the early stages of cosmic development. This is the first such recorded case in history.

The James Webb Space Telescope has enabled another unusual discovery. A team from the University of Oxford has spotted a unique galaxy with it, which existed around one billion years after the Big Bang. The uniqueness of this object lies in the fact that the interstellar gas in the galaxy shines brighter than its stars.

This discovery could be key to understanding the evolution of the universe. It serves as the missing link between the first stars and well-formed galaxies.

"My first thought in looking at the galaxy’s spectrum was, ‘that’s weird,’ which is exactly what the Webb telescope was designed to reveal: totally new phenomena in the early universe that will help us understand how the cosmic story began" says Dr Alex Cameron, who leads the research described in the "Monthly Notices of the Royal Astronomical Society".

Research has shown that observations of galaxy 9422 almost exactly match computer models of gas heated by hot, massive stars. According to Dr Harley Katz, the stars in galaxy 9422 appear to be much hotter and more massive than those in the local universe. This is due to differences between the early and contemporary universes.

In the local universe, typically hot, massive stars reach temperatures from around 70,000°F to 90,000°F. However, according to the team, stars in the discovered galaxy 9422 have temperatures exceeding 140,000°F. According to researchers, the galaxy is in a short phase where many massive, hot stars form in a dense gas cloud. This cloud is exceptionally bright because it is bombarded with many photons emitted by these stars.

Such gas was expected in the vicinity of the first generation of stars – the so-called Population III stars. However, scientists emphasise that this galaxy does not contain Population III stars. Data from the Webb telescope indicate excessive chemical complexity.

"The exotic stars in this galaxy could be a guide for understanding how galaxies transitioned from primordial stars to the types of galaxies we already know," says Dr Katz.

Despite the significant discovery, many questions remain unanswered. Are the observed conditions common in galaxies from that period, or is it a rare phenomenon? Can they provide additional information about the earlier phases of galaxy evolution? – ask the astronomers.