This interactive visualization places 4,260 galaxies in 3D comoving space across the COSMOS field, combining imaging from JWST with spectroscopy from the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) and over 20 years of multi-instrument spectroscopy from the Cosmology Evolution Survey (COSMOS), compiled in the COSMOS spec-z compilation (Khostovan et al. 2026).
HETDEX PDR1 (Hobby-Eberly Telescope Dark Energy Experiment, Public Data Release 1; Mentuch Cooper et al. 2026) provides blind integral-field spectroscopy covering 86.67 deg² at 3470–5540 Å (R∼800), yielding spectroscopic redshifts for hundreds of thousands of emission-line sources.
COSMOS-Web DR1 (Shuntov et al. 2025, A&A 704, A339; Casey et al. 2023, ApJ 954, 31) is a 255-hour JWST treasury survey covering ~0.54 deg² of the COSMOS field in four NIRCam bands (F115W, F150W, F277W, F444W). The postage-stamp images shown here are matched JWST cutouts for each spectroscopic detection.
HETDEX LAE (2,200) — Lyman-alpha Emitters
(z ∼ 1.9–3.5), detected blindly in Hobby-Eberly Telescope (HET)
integral-field spectra (HETDEX PDR1).
HETDEX AGN (65) — Active Galactic Nuclei
detected in HET integral-field spectra (HETDEX PDR1).
Spec-z galaxies (1,995) — Galaxies with
spectroscopic redshifts from the COSMOS spec-z compilation
(Khostovan et al. 2026).
Of the 5,602 HETDEX LAEs in this field, 3,220 (57%) have no JWST imaging counterpart visible in COSMOS-Web. This can arise for two reasons:
(1) Extremely faint host galaxies — many LAEs at z ∼ 2–3 are low-mass, low-luminosity galaxies below JWST’s detection threshold even in deep NIRCam imaging.
(2) False positives — HETDEX detects emission lines blindly across millions of spectra; a fraction of detections are noise fluctuations or instrumental artifacts rather than real sources.
Only LAEs with a JWST match appear as galaxy images in this visualization; the remainder are not shown.
Galaxy images are displayed at 15× their true angular diameter size by default. Each JWST cutout spans 5.0″ on the sky; at 1× each galaxy cutout represents its true comoving extent (DC × 5.0″ in radians — typically ~0.1–0.15 Mpc). The 15× default makes individual galaxies visible across the full 3D volume. Use the Scale slider to adjust from 1× to 50×.
Drag to rotate • scroll to zoom •
click a galaxy to inspect its JWST image and spectroscopic properties.
Fly through animates a camera path through cosmic time.
Redshift Source toggles individual source-type layers.
Scale slider adjusts displayed galaxy size relative to true angular extent.
Mentuch Cooper et al. 2026 (HETDEX PDR1) •
Shuntov et al. 2025, A&A 704, A339 •
Casey et al. 2023, ApJ 954, 31 (COSMOS-Web DR1) •
Khostovan et al. 2026 (COSMOS spec-z compilation).
3D visualization built with Three.js.