Astronomers have identified a massive galaxy that appears to be losing its star-forming gas just 1.4 billion years after the Big Bang, potentially capturing a rare snapshot of a galaxy in the act of dying. This discovery, detailed in a paper posted to the arXiv preprint server on June 16, offers a direct look at a process previously inferred only from the corpses of ancient galaxies.
Known as "red and dead" galaxies, these massive systems ceased forming stars far earlier in cosmic history than expected. Until now, astronomers had only spotted the aftermath — fully quenched galaxies — but had not observed the transition itself. This finding may finally illuminate how such a dramatic shutdown occurs.
The galaxy is being stripped of its star-forming gas, the raw material needed to birth new stars. The precise mechanism behind this gas loss remains unclear, though the researchers outline several clues in their preprint. The event took place when the universe was merely 10% of its current age.
If confirmed, the discovery would mark the first time scientists have witnessed a galaxy in the process of becoming "dead," providing a critical test for models of galaxy evolution. It suggests that some early galaxies underwent a rapid, violent end to star formation rather than a slow fade.
The findings are preliminary, as they have not yet been peer-reviewed. Further observations with telescopes like JWST may be needed to confirm the mechanism and rule out alternative explanations.