Detailed analysis of light from galaxies that existed early in the formation of the universe has revealed the highest levels of metals at that time. Scientists are still unable to clearly show the origin of the heavy elements they observed. These are likely elusive “host stars,” making this discovery one of the most important in astrophysics. Science believes that almost all metals are born in stars and can exist for the first time. Supernova explosions scatter them even further. All of us, the Earth, and all living and non-living things that live on it, were once atoms born in stars. Let me be clear that astrophysics considers anything heavier than hydrogen or helium to be a metal. The Big Bang primarily produced hydrogen. Helium was significantly reduced, lithium was further reduced, and perhaps small amounts of beryllium were present. So the metallicity of the universe increased gradually and completely predictably, allowing us to imagine the evolution of stars, galaxies, and everything else. But observations of the early universe made possible by the James Webb Telescope are beginning to question our understanding of the processes inside the universe.

One such discovery was the discovery of fairly impressive amounts of carbon in young (or relatively old) galaxies some 350 million years after the Big Bang. Remember, too many metals have been discovered in galaxies with a redshift of z12.5, and carbon is a metal to astrophysicists. James Webb spent 65 hours spectroscopically analyzing astronomical objects, an unprecedented feat. The fact that such instruments spend so much time analyzing the spectra of galaxies is a luxury that few people can afford. Analysis of the spectrum and width of carbon present in the light of galaxies suggests that carbon resides in stars rather than in interstellar or intergalactic gas. The star itself cannot be seen from this distance. If we’re lucky, gravitational lensing can distinguish such stars. On the other hand, thanks to Webb, we can conclude that the stars of ancient galaxies were not pure at all. Such galaxies were expected to contain population III stars, which should be metal-free. This is the first generation of stars after the Big Bang, known only hypothetically.

According to the discoveries of scientists, the source of carbon in ancient galaxies is probably stars with population III. Another source of carbon in observed galaxies could be supermassive black holes. Absorption of substances through the holes may be accompanied by the formation of metals. However, the probability of that happening seems much lower. Finally, other metals can also be synthesized in supernovae and ejected into space from AGB (asymptotic giant bifurcation) stars. But for this to happen, AGB stars would need to evolve significantly longer than they have been observed.