From a joint Sorbonne University/CNRS press release dated September 2, 2026. Based on a paper published in The Open Journal of Astrophysics to which the CRAL contributed: “A GLIMPSE of the 99%: a census of the faintest galaxies during the epoch of reionization and its implications for galaxy formation models.” Thumbnail: “A glimpse into the distant past.” © ESA/Webb, NASA, and CSA, H. Atek, M. Zamani (ESA/Webb). Acknowledgments: R. Endsley.
An international team of astrophysicists has observed and cataloged the smallest and faintest galaxies in the early Universe. These galaxies, which were previously invisible, confirm their pivotal role in the transformation of the Universe more than 13 billion years ago. This study, led by Hakim Atek of the Paris Institute of Astrophysics (CNRS/Sorbonne University) as part of the James Webb Space Telescope’s (JWST) GLIMPSE program, has just been published in The Open Journal of Astrophysics.
The GLIMPSE program is an ultra-deep observation program conducted using the JWST’s NIRCam instrument. It focuses on using gravitational lenses to probe the far reaches of the early Universe, providing the deepest images ever obtained to date.
Until now, our understanding of the reionization era—when the first stars illuminated and ionized the gas in the universe—has relied on the brightest galaxies, which account for only 1 to 10 percent of all galaxies. This study, titled “A Glimpse of the 99%,” delves for the first time into the remaining 99%—the so-called faint galaxies. By using the Abell S1063 galaxy cluster as a gigantic natural magnifying glass (via a phenomenon called gravitational lensing), the team of researchers was able to amplify the light from extremely distant sources.
Reference
« A GLIMPSE of the 99%: a census of the faintest galaxies during the epoch of reionization and its implications for galaxy formation models ». Atek, Hakim, Iryna Chemerynska, Lukas J. Furtak, Johan Richard, John Chisholm, Vasily Kokorev, Michelle Jecmen, et al. 11 August 2026, The Open Journal of Astrophysics.
DOI: https://doi.org/10.33232/001c.166816