The Webb telescope detects much more light than expected in the early universe

The ‘oldest’ galaxies created 10 times more ultraviolet photons than predicted by scientific models

An international team of researchers has analyzed the deepest images captured by the James Webb Space Telescope and has discovered that the early universe – the oldest – harbors many more galaxies, much brighter and smaller than expected.

Led by Pablo G. Pérez-González, from the Center for Astrobiology (CAB), CSIC-INTA, and carried out by researchers from eight European countries and the United States, the work presents the results of the study of the most distant galaxies in the universe obtained with data from the NIRCam instrument on the James Webb telescope.

Details of the research have been published in The Astrophysical Journal Letters. For the investigation, the team took data from an area of the sky known as the Hubble Ultra-deep Field, an area that the Hubble telescope could not access and that can now be explored thanks to the MIRI instrument on James Webb, capable of working in the mid-infrared and observe cold or very distant objects.

The team also made observations with the NIRCam instrument, Webb’s most sensitive camera, which allowed them to detect some of the most distant galaxies observed to date, 10 times fainter than those studied during the first 6 months of the orbit. mission.

Thanks to these observations, the team found 44 galaxies that would have formed in the first 500 million years of the Universe, less than 4% of their current age, including some candidates formed in the first 200 million years of the Universe, a 1% of the age.

The team compared the properties of these early galaxies with what was predicted by the most advanced galaxy formation models and made by the world’s most powerful supercomputers.

“For decades simulations of the universe have been developed that have studied how galaxies are formed, when the first stars appear, how the primordial gas, which was only hydrogen and helium, is converted into other elements, such as oxygen or carbon, and how, ultimately, the fundamental ingredients of life are created”, explains Luca Costantin, CAB researcher and co-author of the article.