Particle.news
Download on the App Store

JWST Produces Most Detailed Dark-Matter Map to Date

A weak-lensing analysis of 800,000 galaxies in the COSMOS field using 255 hours of NIRCam imaging infers mass at roughly twice the previous resolution.

Overview

  • The map reveals fine filaments, bridges, and small halos in addition to large cluster concentrations.
  • Comparisons with visible-matter tracers and X‑ray sources show a tight spatial correspondence in the mapped region.
  • The mapped sky area spans a patch near Sextans about 2.5 times the apparent size of the full Moon.
  • The dataset includes about twice as many background galaxies as prior Hubble maps of the field, enabling sharper reconstruction of the mass distribution.
  • The study, led by Diana Scognamiglio for the COSMOS‑Webb collaboration, is published in Nature Astronomy, with wider coverage expected from ESA's Euclid mission and NASA's Roman telescope.