The Surprising Findings
Astronomers using the James Webb Space Telescope (JWST) have made a fascinating discovery about galaxies in the early universe. Contrary to our expectations, these galaxies have less heavy elements, or metals, than we would predict based on our understanding of closer galaxies in the relatively recent universe.
Evidence of Different Physics
The study, led by Kasper Heintz from the University of Copenhagen in Denmark, focused on 16 galaxies that formed within the first 750 million years after the big bang. The team found that these galaxies are diluted by pristine gas without metals. This suggests that the physics driving galaxy formation and evolution at these early stages is drastically different from what we observe today.
An Intimate Connection to Surroundings
Unlike galaxies in the nearby universe, these early galaxies are not as independent of their surroundings. They are closely connected to the surrounding intergalactic or circumgalactic gas. This challenges the notion of treating them as individual “ecosystems” and emphasizes the need to understand their interactions with the surrounding gas.
Amplifying the Understanding Gap
These new findings add to the growing list of anomalies observed by the JWST in early galaxies. In addition to having fewer metals, these galaxies are also far more massive and abundant than expected. The large amounts of gas required to dilute them further contribute to their shocking massiveness. This raises further questions about our understanding of galaxy evolution at the earliest epochs.
Topics:
- Galaxies
- James Webb Space Telescope
