The big galaxy in the foreground is named LEDA 2046648, and is seen just over a billion years back in time, while most of the others lie even farther away, and hence are seen even further back in time. (ESA/Webb, NASA & CSA, A. Martel)

A ream of Danish researchers believes they have observed some of the first galaxies using the James Webb Space Telescope. These galaxies are so old that they are probably still forming. The ratio of galaxies to heavy elements has remained constant in the local Universe throughout the past 12 billion years of history. However, astronomers understand that the first galaxies were different: they had not yet gone through cycles of star formation and death that enriched gas clouds with metals, elements heavier than hydrogen and helium.

Danish astronomers analyzed light from 16 early galaxies. Observations show that the chemical abundance in these galaxies is 25% lower than in galaxies that formed later. Observations show that early galaxies remain tightly bound to the intergalactic medium and are subject to a constant influx of primordial gas, which effectively dilutes their “metal abundance.” fruit. The new results contrast sharply with existing models, which suggest that galaxies have evolved in an equilibrium fashion throughout the history of the Universe, where there is a relationship between the number of stars formed and the amount of atoms. heavy factor.

However, according to the researchers, this result is not too surprising: it is exactly what theoretical models of galaxy formation predict. Kasper Elm Heinz, assistant professor at the Center for Cosmic Dawn at Niels Bohr, said: “This result gives us our first insight into the early stages of galaxy formation, as it turns out is more closely related to intergalactic gas than we thought.” Academy.

However, according to the researchers, this result is not too surprising: it is exactly what theoretical models of galaxy formation predict. Kasper Elm Heinz, assistant professor at the Center for Cosmic Dawn at Niels Bohr, said: “This result gives us our first insight into the early stages of galaxy formation, as it turns out is more closely related to intergalactic gas than we thought.” Academy.

source: https://www.nature.com/articles/s41550-023-02078-7