Recent observations of JADES-GS-z11-0, a distant galaxy, have revealed surprising levels of oxygen. This discovery was made possible thanks to the James Webb Space Telescope and the ALMA interferometer, located in Chile. Researchers have refined the distance of this galaxy, now estimating it to be 400 million years after the Big Bang.
The abundant presence of oxygen suggests several stellar life cycles. Massive stars produce this element through nuclear fusion before expelling it when they explode—processes that normally take billions of years to enrich a galaxy. Here, everything happened in record time.
Simulation of Population III stars, 400 million years after the Big Bang.
Image Wikimedia
Star formation in JADES-GS-z11-0 is extremely active, with six solar masses created annually. This rate far exceeds that of our Milky Way. Such productivity partly explains the rapid accumulation of heavy elements, with conditions favoring accelerated evolution.
This discovery opens perspectives on the early emergence of life. Oxygen is essential for many biological forms, as are carbon or silicon. Although speculative, this implies that the ingredients for life were available very early. Exoplanets in such galaxies may have inherited these elements.
Cosmological models must integrate this new data: the speed of chemical enrichment upends standard galactic formation scenarios. Further studies with ALMA and JWST are planned to refine these results.
How do stars produce oxygen?
Stars generate oxygen through nuclear fusion in their cores. This process transforms hydrogen into heavier elements under the effect of gravity and heat. In massive stars, advanced fusion creates carbon, then oxygen, and finally elements like neon or magnesium. The amount produced depends on the star's mass and lifespan.
When these stars die in supernovae, they expel these elements into space. This enrichment allows new generations of stars and planets to form with diverse materials. Without this cycle, the Universe would lack elements essential to life. The oxygen detected in JADES-GS-z11-0 testifies to several such cycles in a short time.
Why was the young Universe so active?
The primordial Universe was denser and hotter, promoting rapid star formation. The first galaxies contained a lot of gas unpolluted by heavy elements. This initial purity allowed stars to form efficiently, without hindrance. Gravitational interactions were also more intense, accelerating collisions and galactic mergers.
Moreover, the absence of heavy elements meant that stars could be very massive and live briefly, quickly enriching their environment. This contrasts with the current Universe, which is calmer and more evolved.
These extreme conditions explain why galaxies like JADES-GS-z11-0 were able to reach chemical maturity so quickly, contradicting the predictions of current models.