The farthest carbon ever seen has been discovered by the James Webb Space Telescope (JWST) in a galaxy that we see as it existed just 350 million years after the Big Bang.
The detection is notable because not only is it the oldest known carbon, it is also the first time that an element heavier than hydrogen or helium – what astronomers call ‘metals’ – has been confirmed at a very early stage. universe.
‘Previous research suggested that carbon started forming in large quantities relatively late – about a billion years later Big bang,” said Roberto Maiolino, from the Kavli Institute for Astronomy at the University of Cambridge in England, in a rack. “But we’ve discovered that carbon was formed much earlier — it could even be the oldest metal of all.”
Related: What is the Big Bang Theory?
The universe’s hydrogen and helium were created in the furnace of the Big Bang, but aside from an extra dash of lithium, every other element had to wait to come from stars. Nuclear fusion reactions in those stars create carbon, oxygen, nitrogen and so on, while the raw energy from a supernova explosion can create many other, even heavier, elements, just like neutron star mergers.
Many of these elements, especially carbon, are crucial for forming planets and life as we know it, but it took many generations of stars to build up enough carbon and other metals to be detectable and useful at such great distances. are in cosmic chemistry. .
however, the JWST‘s detection of carbon in the universe GS-z12 — found at a redshift of 12.5, which amounts to a lookback time of 13.4 billion years, suggests that stars lived rapidly during the formative years of the cosmos. Many generations must have come and gone in rapid succession to build up detectable amounts of carbon in such a short time. (The Big Bang happened about 13.8 billion years ago.)
“We were surprised to see carbon so early in the universe, because the earliest stars were thought to produce much more oxygen than carbon,” says Maiolino. ‘We had thought that carbon was enriched much later, by completely different processes, but the fact that it appears so early tells us that the very first stars might have worked very differently.”
GS-z12 is a compact galaxy with a low mass compared to ours Milky Way but is relatively large for the early time period in which we find it, an age populated by small but fast growing galaxies.
“It’s just an embryo of a galaxy when we observe it, but it could grow into something very big, about the size of the Milky Way,” said Francesco D’Eugenio of the Kavli Institute, who led the study.
The discovery of carbon so early may change what we know about the course of cosmic chemistry. Carbon is an essential part of cosmic dust grains, which clump together to build larger objects – asteroids, planetestimals, and finally the planets themselves. The Earth is believed to be composed largely of carbonaceous objects. Carbon is also an essential part of life as we know it.
“The very first stars are the holy grail of chemical evolution,” D’Eugenio said. “Because they consist only of original elements [i.e hydrogen and helium exclusively]they behave very differently from modern stars. By studying how and when the first metals formed in stars, we can pinpoint a time frame for the first steps on the path that led to the formation of life.”
The JWST’s Near-Infrared Spectrometer (NIRSpec), which detected the carbon, also found hints of oxygen and neon in GS-z12, but more data is needed to confirm the existence of these elements.
Although the carbon in GS-z12 is confirmed to be the earliest metal, the galaxy may not hold the record for long. Astronomers using the JWST have discovered what the… highest redshift galaxy yet discovered, with a redshift of 14.2, which places it only 290 million years after the Big Bang. Oxygen’s absorption line has been detected in its spectrum, but that discovery still needs to be approved through peer review. Once published in a journal, it will be the earliest example of an element heavier than hydrogen or helium.
Whatever the case, the new finding shows that elements could be produced in significant quantities in the early universe and that stars at the time lived and died faster than astronomers realized.
Furthermore, the presence of carbon and oxygen in the early universe means that astronomers and astrobiologists may also be able to start talking about the existence of planets and perhaps also about life earlier in the universe.
The discovery of carbon in GS-z12 will be published in a future issue of Astronomy & Astrophysics, but a preview of the paper is available here.