The James Webb Space Telescope (JWST) has observed the most distant galaxy detected to date, emerging just 280 million years after the formation of the universe. This discovery once again highlights JWST's capability to unveil the earliest phases of cosmic history.
The newly discovered galaxy has been named "MoM-z14." The discovery was made as part of the Mirage (or Miracle) spectroscopic survey aimed at observing the early universe.
The galaxy's redshift value was measured at z = 14.44, indicating that its light was emitted about 13.5 billion years ago.
Previously, the record was held by the galaxy JADES-GS-z14-0 with a redshift of z = 14.32. However, MoM-z14 pushes the boundaries of the observable universe even further.
According to a study led by Rohan Naidu from the MIT Kavli Institute for Astrophysics and Space Research, published on arXiv.org, this galaxy may have formed at a time extremely close to when the universe's first stars were born.
The researchers said, "JWST has revealed a population of unexpectedly bright galaxies, raising fundamental questions about galaxy formation."
Spectroscopic analysis showed that most of MoM-z14's light comes from stars. In other words, the galaxy shines not because of an active galactic nucleus (AGN) powered by a supermassive black hole, but due to a large number of stars, likely including supermassive stars.
Moreover, the galaxy's nitrogen-to-carbon ratio is higher than the Sun's. This ratio points to a chemical composition similar to that found in ancient globular star clusters associated with the Milky Way. The researchers suggest this similarity offers clues linking galaxy evolution across cosmic time.
Two different structures were observed in MoM-z14 and similar galaxies: compact (point-like) and diffuse (extended) morphologies. Compact galaxies show strong nitrogen emission, while diffuse structures have weaker nitrogen signals. This suggests a direct relationship between a galaxy's chemistry and its physical structure.
The authors note that galaxies like MoM-z14 could lead to fundamental changes in our understanding of galaxy formation. If not canceled, upcoming missions such as the Nancy Grace Roman Space Telescope are expected to discover hundreds more of such galaxies in the coming years.
"JWST is expanding our observable horizon of the universe's earliest epochs to unimaginable levels. The era of the first stars is no longer far beyond our reach."
