What you're looking at
JWST's largest survey to date — COSMOS-Web — pointed at a single contiguous patch of sky roughly the angular size of three full moons (~0.54 deg²) and went deep enough to detect galaxies down to log(M⋆/M☉) ≈ 8.7 at z = 7. Hatamnia et al. 2025 then applied a weighted kernel-density estimator to the resulting 160,047-galaxy photo-z catalog, producing a slice-by-slice reconstruction of the cosmic web from the local Universe back to a few hundred million years after the Big Bang. This map is that reconstruction — every released galaxy in its place, colored by its KDE-derived overdensity 1+δ.
How to read the cone
The observer sits at the origin (lower-left in the default side view). The line-of-sight axis stretches outward in comoving Mpc — short at low-z, long at high-z. The transverse axes are the on-sky offsets in dRA·cos(Dec) and dDec, multiplied by the comoving distance at each galaxy's redshift, then exaggerated by a user-controlled factor (default 30×) because the survey's pencil-beam aspect ratio — a 9,300-Mpc-deep stick only ~160 Mpc wide at the far end — is otherwise unreadable. Drop the exaggeration to 1× to see the true geometric proportions.
Filaments and nodes emerge wherever the gold (high-1+δ) galaxies pile up along contiguous structures. Voids are the dim regions where only blue-grey (1+δ ≲ 1) points scatter. The pile-ups around z ≈ 2–3 are the proto-clusters Hatamnia et al. identify as the first crystallized nodes of the modern cosmic web — sites where mass assembly was already running ahead of the cosmic mean by the first few billion years.
What's NOT in this map
This is the released LSS catalog, not the full COSMOS-Web photometric catalog (~700k sources). The COSMOS-Web team's selection for the LSS analysis keeps only galaxies with robust photo-z at z ≥ 0.4 and well-converged mass fits. Spectroscopic redshifts from the DESI/COSMOS-VR/SUBARU FMOS programs are folded in as priors but do not survive the public release as a separate flag. The 2D per-slice density images (DENSITY_###, DENSITYCONTRAST_###) — also part of the FITS — are not rendered here; they're the textbook "slice cards" you've seen in the press kit and live behind the Foundations chapter.
Provenance
catalog.fits (289 MB). The OVERDENSITY table is used here for (RA, Dec, density_excess); per-galaxy z is assigned from the POINTS table by taking the slice in which each galaxy carries the maximum statistical weight, then looked up against the SLICES table's slice-center redshift.
Pipeline: Hatamnia et al. 2025 — weighted kernel-density estimation on photo-z with adaptive bandwidth and boundary correction (github.com/hhatam/CosmicWeb).
Cosmology: Flat ΛCDM, H₀ = 70 km/s/Mpc, Ω_m = 0.30, Ω_Λ = 0.70 — adopted here to match the convention used in the COSMOS-Web reductions. Comoving distance computed by Simpson-rule integration of c/H(z) on a 401-point grid.
References
- Hatamnia, H., Mobasher, B., Taamoli, S., et al. 2025 — Large-Scale Structure in COSMOS-Web: Tracing Galaxy Evolution in the Cosmic Web up to z ∼ 7 with the Largest JWST Survey. ApJ 990:114 · arXiv:2511.10727 · DOI 10.3847/1538-4357/ae5bac
- Casey, C. M., Kartaltepe, J. S., et al. 2023 — COSMOS-Web: An Overview of the JWST Cycle 1 Treasury Program. ApJ 954:31. Survey design and footprint.
- Taamoli, S., Mobasher, B., et al. 2024 — The Large-Scale Structure of the Universe from Hubble: COSMOS-Web Predecessor. ApJ 966:18. Earlier reconstruction on the same field; the JWST jump compared against here.
- Chartab, N., Mobasher, B., et al. 2020 — The Cosmos Evolution Survey: Density Estimation and Galaxy Evolution. ApJ 890:7. The KDE-with-photo-z machinery this catalog uses.
- Darvish, B., Mobasher, B., et al. 2015 — The Effects of the Local Environment and Stellar Mass on Galaxy Quiescence. ApJ 805:121. Origin of the weighted-KDE method.
- UCR News — Astronomers produce most detailed map of the cosmic web, 2026-05-11. Press release (news.ucr.edu).