JWST's COSMOS-Web Survey Maps 164,000 Galaxies Into the Most Detailed Cosmic Web Yet, Stretching Back to When the Universe Was a Billion Years Old
A UC Riverside-led team used the largest JWST observing program to trace galaxies along the cosmic web from today out to redshift z ~ 7, and released the full pipeline and catalog publicly.
Overview
An international team led by the University of California, Riverside has used the largest James Webb Space Telescope observing program to date to produce what its authors describe as the most detailed map of the cosmic web ever assembled, threading 164,000 galaxies through a contiguous patch of sky roughly the size of three full Moons. The work, published in The Astrophysical Journal, traces the network of galaxies, gas, and dark matter from the present day back to when the universe was about one billion years old, according to a UC Riverside announcement summarized by ScienceDaily.
What We Know
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,” appears in The Astrophysical Journal under DOI 10.3847/1538-4357/ae5bac, as Phys.org reports. The lead author is Hossein Hatamnia, a graduate student at UC Riverside and Carnegie Observatories, with Bahram Mobasher, a distinguished professor of physics and astronomy at UC Riverside, serving as advisor and study investigator, per the UCR release.
The analysis is built on COSMOS-Web, which UCR describes as the largest General Observer program selected for JWST, covering a contiguous sky area approximately the size of three full Moons. From that field the team catalogued 164,000 galaxies and used their positions and distances to reconstruct the filaments and clusters of the cosmic web across 13.7 billion years of cosmic history, reaching back to a maximum redshift of about z ~ 7, Phys.org notes.
“JWST has completely changed our view of the universe, and COSMOS-Web was designed from the start to give us the wide, deep view we need to see the cosmic web,” Hatamnia said in the UCR announcement. According to Engadget, he added that “for the first time we can study the evolution of galaxies in cluster and filamentary structures across cosmic time, all the way from when the universe was a billion years old up to the nearby universe.”
Mobasher characterized the improvement over previous surveys in similarly direct terms. “The jump 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,” he told Engadget. SciTechDaily records a complementary remark from Hatamnia on the underlying advantage of the instrument: “The telescope detects many more faint galaxies in the same patch of sky, and the distances to those galaxies are measured far more precisely.”
What Was Released
The team published the analysis pipeline, the galaxy catalog, and a visualization of the evolving structure alongside the paper itself. “The pipeline used to build the map, the catalog of 164,000 galaxies and their cosmic density, and a video showing the cosmic web evolving across billions of years, has been released to the public,” Mobasher said in a quote carried by EurekAlert! and SciTechDaily.
The project is an international collaboration, with co-authors drawn from the United States, Denmark, Chile, France, Finland, Switzerland, Japan, China, Germany, and Italy, the UCR release lists. Funding for the work came from the European Union’s Horizon 2020 research and innovation program, per EurekAlert!.
JWST itself launched in 2021 and operates primarily in the infrared, allowing it to detect very faint, very distant galaxies that earlier surveys could not resolve, as SciTechDaily explains. The cosmic web — the large-scale arrangement of dark matter, gas, and galaxies into filaments and sheets separated by voids — is the structural skeleton that determines where galaxies form and evolve, Engadget notes.
What We Don’t Know
The announcement does not disclose what fraction of the 164,000-galaxy catalog falls into the highest-redshift bins, nor how spectroscopic confirmation is distributed across the sample. The paper title cites a coverage of “up to z ∼ 7,” but the press materials do not break out how densely the cosmic web is reconstructed at the furthest distances versus in the lower-redshift regime where galaxy counts are highest.
The sources also do not specify which JWST instruments contributed to the catalog or the wavelength bands used to construct it, though the paper itself, available via DOI 10.3847/1538-4357/ae5bac, is the authoritative reference for those technical details, per Phys.org.
Finally, while the team describes its map as the most detailed reconstruction of the cosmic web to date, the press materials do not directly compare its filament-tracing accuracy with prior wide-field surveys such as those built on Hubble or large ground-based programs, leaving that comparison to be made in the peer-reviewed paper and follow-up analyses.