JWST maps cosmic web back 13 billion years

The COSMOS-Web team has released a new map of the cosmic web built from James Webb Space Telescope data, tracing the universe’s large-scale structure across roughly 13.7 billion years of cosmic history. The project uses the largest JWST survey so far, covering a patch of sky about the size of three full Moons. Researchers said the map follows galaxy networks back to when the universe was about 1 billion years old. The underlying study appears in *The Astrophysical Journal* and describes the reconstruction of large-scale structure up to redshift 7. ### How far back does this map actually go? The new reconstruction reaches to redshift 7, according to the paper titled “Large-Scale Structure in COSMOS-Web: Tracing Galaxy Evolution in the Cosmic Web up to z ∼ 7 with the Largest JWST Survey.” In time terms, that corresponds to the universe’s first billion years, the team said in release material describing the result. The map is presented as a slice through nearly 14 billion years of cosmic history, with galaxies placed by distance in cosmic time from the nearby universe to the early universe. (rit.edu) ### What is COSMOS-Web measuring in this survey? COSMOS-Web is a 255-hour JWST Cycle 1 treasury program that maps a contiguous 0.6 square-degree area with NIRCam imaging and a non-contiguous 0.2 square-degree area with MIRI in parallel, according to the survey’s official page. The program was designed to contain about 1 million galaxies across cosmic time and to study reionization, massive galaxy evolution and large-scale structure. The sky area used for the map is roughly equivalent to three full Moons, according to project material and university summaries of the release. (iopscience.iop.org) ### What makes this map different from earlier ones? The COSMOS-Web team said the new release is the most detailed map yet of the cosmic web, the network of filaments, clusters and voids that shapes the large-scale arrangement of galaxies. Bahram Mobasher of the University of California, Riverside said in public release material that the large-scale structure identified from the JWST data is more informative than earlier maps of the same sky region made with the Hubble Space Telescope. (cosmos.astro.caltech.edu) Release materials said side-by-side comparisons show JWST resolving structures that earlier data had smoothed over. ### Who produced the map? Researchers at the University of California, Riverside led the effort described in university release material, with Hossein Hatamnia as lead author on the paper and Bahram Mobasher among the senior researchers. The broader COSMOS-Web survey is co-led by Jeyhan Kartaltepe of Rochester Institute of Technology and Caitlin Casey of the University of California, Santa Barbara, according to the official survey page. RIT said the COSMOS-Web team released the map publicly this week. (rit.edu) ### What can scientists and the public see now? The COSMOS-Web public data release page says users can access reduced NIRCam and MIRI mosaics, photometric catalogs, photometric redshifts and physical properties for about 780,000 galaxies, plus an interactive map viewer over the full field. The same release page says large-scale structure density maps up to z = 7 are available under additional data products. Public release material also said the pipeline used to build the map, a catalog of 164,000 galaxies and their cosmic density, and a video showing the cosmic web evolving across billions of years have been released. (iopscience.iop.org) ### What comes next from this release? The COSMOS-Web release gives astronomers a public dataset they can use to test how galaxy properties change across filaments, clusters and voids over time. The official data page shows the release remains active, with updates posted as recently as May 4, 2026, including revised catalog files and added morphological measurements. The survey page lists Jeyhan Kartaltepe and Caitlin Casey as contacts for the program, and the interactive viewer and downloadable products are now live through the COSMOS-Web public release site. (cosmos2025.iap.fr)