NASA’s James Webb Space Telescope (JWST) has identified the most distant galaxy ever observed, located a mere 290 million years after the Big Bang.
The world’s most powerful space telescope has done it again.
Webb has discovered what appears to be a new record-holder for the most distant known galaxy — shattering its own previous record. This galaxy existed only 290 million years after the big bang: https://t.co/6JN3L2CvRG pic.twitter.com/pbshZ2H0GC
— NASA Webb Telescope (@NASAWebb) May 30, 2024
This discovery, headed by a global team of astronomers, sheds new light on the early universe and challenges existing theories of galaxy formation.
About NASA’s JWST
Over the last two years, scientists have used the JWST to probe what astronomers call Cosmic Dawn—the era within the first few hundred million years following the Big Bang when the first galaxies emerged. These early galaxies are key to understanding the transformations in gas, stars and black holes during the universe’s infancy. The JWST Advanced Deep Extragalactic Survey (JADES) program, using the telescope’s NIRSpec (Near-Infrared Spectrograph), has unveiled a galaxy observed just 290 million years post-Big Bang, corresponding to a redshift (term used to describe distances) of 14.32.
Discovery
The galaxy, designated JADES-GS-z14-0, was initially identified in early 2023 as a candidate high-redshift galaxy. The source was unusually bright and situated close to another galaxy, prompting further interest. Observations in October, 2023 and January, 2024 confirmed its status. Using Webb’s NIRCam (Near-Infrared Camera) and NIRSpec, the team captured detailed spectra over nearly ten hours, establishing JADES-GS-z14-0 as the most distant known galaxy.
Properties and Implications
JADES-GS-z14-0’s brightness and size—spanning over 1600 light-years—imply it is several hundred million times the mass of the Sun, primarily consisting of young stars rather than light emissions from a supermassive black hole. This raises questions about how such a massive galaxy could form within such a brief period post-Big Bang.
Stefano Carniani from Scuola Normale Superiore in Pisa and Kevin Hainline from the University of Arizona highlighted the galaxy’s luminosity and proximity to another galaxy. This proximity initially complicated its classification but deeper imaging with Webb’s NIRCam confirmed its high-redshift status. Moreover, JADES-GS-z14-0 was detected at longer wavelengths using Webb’s MIRI (Mid-Infrared Instrument) which indicated the presence of strong ionized gas emissions from hydrogen and oxygen. The presence of oxygen so early suggests that multiple generations of massive stars had already lived and died.
Challenging Theoretical Models
The characteristics of JADES-GS-z14-0 contradict theoretical models and simulations of early universe galaxies, suggesting that such bright and massive galaxies were more common than previously thought. This finding implies a re-evaluation of the number of bright galaxies expected to be observed in the early universe.
The discovery was part of Guaranteed Time Observations (GTO) program 1287 with MIRI observations under GTO program 1180.
