Scientists solve mystery of one of most distant galaxies

Scientists have, for the first time, managed to solve the puzzle of the unusual chemical composition of one of the most distant galaxies in the Universe. This is reported in an article published in The Astrophysical Journal Letters.

The galaxy GN-z11 emerged about 440 million years after the Big Bang. However, spectra obtained by the Webb telescope revealed an unusually high nitrogen content in GN-z11. This had long been a puzzle since elements heavier than hydrogen and helium are formed in stars and distributed in the interstellar medium in the latter stages of their lives, billions of years after their formation.

According to one hypothesis, the high nitrogen content in the early Universe is explained by the presence of short-lived supermassive stars, which are 50-100 thousand times more massive than the Sun. However, the new study proposes a new source of nitrogen — intermittent star formation with a quiescent phase lasting about 100 million years.

After the second burst of star formation, Wolf-Rayet stars emerge — stars with very high temperature, luminosity, and a mass of up to 120 times that of the Sun. It is these stars that become the dominant source of nitrogen enrichment in the interstellar medium. According to the authors, other scenarios do not satisfy the observed data.