An ultra-high-resolution map of (dark) matter
Journal article, 2026
Ordinary matter—including particles such as protons and neutrons—accounts for only about one-sixth of all matter in the Universe. The rest is dark matter, which does not emit or absorb light but plays a fundamental role in galaxy and structure evolution. Because it interacts only through gravity, one of the most direct probes is weak gravitational lensing: the deflection of light from distant galaxies by intervening mass. Here we present an extremely detailed, wide-area weak-lensing mass map covering 0.77° × 0.70°, using high-resolution imaging from the James Webb Space Telescope as part of the COSMOS-Web survey. By measuring the shapes of 129 galaxies per square arcminute—many independently in the F115W and F150W bands—we achieve an angular resolution of 1.00±0.01′. Our map has more than twice the resolution of earlier Hubble Space Telescope maps, revealing how dark and luminous matter co-evolve across filaments, clusters and underdensities. It traces mass features out to z ≈ 2, including the most distant structure at z ≈ 1.1. The sensitivity to high-redshift lensing constrains galaxy environments at the peak of cosmic star formation and sets a high-resolution benchmark for testing theories about the nature of dark matter and the formation of large-scale cosmic structure.
Author
Diana Scognamiglio
California Institute of Technology (Caltech)
Gavin Leroy
Durham University
David Harvey
Swiss Federal Institute of Technology in Lausanne (EPFL)
Richard Massey
Durham University
Jason Rhodes
California Institute of Technology (Caltech)
Hollis B. Akins
University of Texas
Malte Brinch
Millenium Nucleus for Galaxies (MINGAL)
University of Chile (UCH)
Edward Berman
Northeastern University
Caitlin M. Casey
Cosmic Dawn Center (DAWN)
University of California
University of Texas
Nicole E. Drakos
University of Hawaii
A. Faisst
California Institute of Technology (Caltech)
M. Franco
University Paris-Saclay
University of Texas
Leo W.H. Fung
Durham University
Ghassem Gozaliasl
Aalto University
University of Helsinki
Qiuhan He
Durham University
University of Groningen
Hossein Hatamnia
University of California
Eric Huff
California Institute of Technology (Caltech)
Natalie B. Hogg
University of Cambridge
Laboratoire Univers et Particules de Montpellier
O. Ilbert
Laboratoire d'Astrophysique de Marseille
Jeyhan S. Kartaltepe
Rochester Institute of Technology
Anton M. Koekemoer
Space Telescope Science Institute (STScI)
Shouwen Jin
Technical University of Denmark (DTU)
Cosmic Dawn Center (DAWN)
Erini Lambrides
National Aeronautics and Space Administration (NASA)
Alexie Leauthaud
University of California
Zane D. Lentz
Durham University
Daizhong Liu
Chinese Academy of Sciences
Guillaume Mahler
University of Liège
Durham University
Claudia Maraston
University of Portsmouth
Crystal L. Martin
University of California
Jacqueline McCleary
Northeastern University
James W. Nightingale
Newcastle University
Bahram Mobasher
University of California
Louise Paquereau
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Institut d 'Astrophysique de Paris
Sandrine Pires
University Paris-Saclay
Brant Robertson
University of California
D. B. Sanders
University of Hawaii
Claudia Scarlata
College of Science and Engineering
Marko Shuntov
Niels Bohr Institute
Cosmic Dawn Center (DAWN)
Greta Toni
Istituto nazionale di astrofisica (INAF)
University of Bologna
Heidelberg University
Maximilian von Wietersheim-Kramsta
Durham University
J. R. Weaver
Massachusetts Institute of Technology (MIT)
University of Massachusetts
Nature Astronomy
23973366 (eISSN)
Vol. In PressInfrastructure
Onsala Space Observatory
Subject Categories (SSIF 2025)
Astronomy, Astrophysics, and Cosmology
DOI
10.1038/s41550-025-02763-9