James Webb telescope’s largest-ever map of the universe unmasks hidden corners
Astronomers have reconstructed the “skeleton” of the universe in unprecedented detail, thanks to the largest survey ever conducted. James Webb Space Telescope (JWST). The resulting map shows how galaxies have evolved since the universe’s early stages about 13 billion years ago and how they fall together into a vast structure called the cosmic web.
The cosmic web is the largest known structure in existence, home to countless galaxy clusters and clusters of clusters. It is the framework of the universe, a scaffold of gas filaments, stars, empty spaces, and sheets of dark matter that reveals the entire large-scale organization of the universe.
In a paper published on May 6 The Astrophysical JournalAn international team of astronomers led by researchers at the University of California, Riverside (UCR) used a wealth of JWST data to shed light on how the universe has evolved.
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New research reveals how internal and external factors influence the formation and death of stars – and hence, galaxies and galaxy clusters – over vast stretches of cosmic time.
Yet what may seem like a tragic turn is the peak era of star formation billions of years behind us. The new research offers additional evidence of how the structural framework of the universe facilitated this transition.
“We show how the cosmic web helped shape the evolution of the galaxy before, during, and after that extreme era,” said study co-author and UCR astronomer E.J. Hossein Hatmaniya Told Live Science via email. “At earlier times, dense regions appeared to be sites of rapid galaxy evolution, while at later times dense environments were associated with the cessation of star formation.”
Such revelations come courtesy cosmos-webThe largest JWST survey ever: a 255-hour program spanning a contiguous region of the sky shaped like three full moons.
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Compared to the previous COSMOS2020 survey, in 2021 shared and conducted by Hubble Space Telescope and other features, the JWST-derived COSMOS-Web boasts better redshift precision and includes more galaxies – including lighter, less-massive and more distant objects. (Redshift is a measure of cosmic distance and time based on how light is redshifted into red wavelengths as it traverses the universe.)
Compared to the JWST-derived image below, which shows a slice of the universe as it appeared 11.5 billion years ago, previous cosmic maps were sparser, more extensive, and lacking cosmic structures.
Data from the new COSMOS-Web survey (left) compared to the previous iteration (right). The sensitivity and depth of the JWST has allowed scientists to map the cosmic web in unprecedented detail.
(Image credit: Hatmaniya et al., The Astrophysical Journal, 2026)
Additionally, the older COSMOS2020 survey tended to overestimate the depth in particularly dense cosmic regions, where galaxies grow earlier and larger, and underestimate the depth of the least dense cosmic regions, the researchers said.
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Yet JWST’s cosmic map preserves relative contrasts in cosmic regions. It also suggests that “giant galaxies in dense atmospheres are more likely to be quiescent” – their star-forming capacity dying and being extinguished.
The team theorized that this might be because those galaxies are so massive. Once the halo of dark matter that supports galaxies grows to 1 trillion solar masses, they energize the gas and prevent it from forming new stars. Additionally, active supermassive black holes reduce star formation by producing energy from their dead gas, near-light-speed jet.
The team found that such “mass-related” star-killing mechanisms dominated until about 7 billion years ago – about half the age of the universe.
In the recent Universe, star formation is largely quenched by the atmosphere surrounding galaxies, which may strip material from them or prevent cold gas from accreting and coalescing into stars.
Thanks to the capabilities of the JWST, the large-scale structure and evolution of the universe have been made clearer than ever before, turning blurry blobs into dim, ancient galaxies.
“The leap in depth and resolution is truly significant, and we can now see the cosmic web at a time when the universe was only a few hundred million years old, an era that was essentially out of reach before JWST,” co-author Bahram MobasherA distinguished professor of physics and astronomy at UCR concluded statement.
Hatmaniya, H., Mobasher, B., Tamoli, S., Kartaltepe, J.S., Casey, C.M., Akins, H.B., Brinch, M., Chartab, N., Drakos, N.E., Faist, A.L., Finkelstein, S.L., Franco, M., Giddings, F., Gozaliasal, G., Hadi, A., Hagju, A., Harish, S., Ilbert, O., Jablonka, P.L., . . . Yang, L. (2026). Large-scale structure in the COSMOS-web: Tracing galaxy evolution down to z ∼ 7 in the cosmic web with the largest JWST survey. The Astrophysical Journal, 1002(2), 192. https://doi.org/10.3847/1538-4357/ae5bac
