Large-scale Structure in COSMOS-Web: Tracing Galaxy Evolution in the Cosmic Web up to z ∼ 7 with the Largest JWST Survey

May 2026 • 2026ApJ..1002..192H

Authors • Hatamnia, Hossein • Mobasher, Bahram • Taamoli, Sina • Kartaltepe, Jeyhan S. • Casey, Caitlin M. • Akins, Hollis B. • Brinch, Malte • Chartab, Nima • Drakos, Nicole E. • Faisst, Andreas L. • Finkelstein, Steven L. • Franco, Maximilien • Giddings, Finn • Gozaliasl, Ghassem • Hadi, Ali • Haghjoo, Aryana • Harish, Santosh • Ilbert, Olivier • Jablonka, Pascale L. • Jin, Shuowen • Khostovan, Ali Ahmad • Koekemoer, Anton M. • Laishram, Ronaldo • Liu, Daizhong • Maturi, Matteo • McCracken, Henry Joy • Martin, Crystal L. • Moscardini, Lauro • Scognamiglio, Diana • Shuntov, Marko • Toni, Greta • de la Vega, Alexander • Weaver, John R. • Yang, Lilan

Abstract • We present a reconstruction of the large-scale structure, using the James Webb Space Telescope (JWST) COSMOS-Web program to trace environmentally driven galaxy evolution up to z ∼ 7. We apply a weighted kernel density estimation method to 164,000 galaxies with robust photometric redshifts. We find that stellar mass has a positive correlation with density at all redshifts, which is stronger for quiescent galaxies (QGs) at z ≲ 2.5, while at higher redshifts (2.5 ≲ z ≲ 5.5) this trend is confined to extreme overdense environments, consistent with early mass assembly in protoclusters. The star formation rate (SFR) shows a negative trend with density for QGs at z ≲ 1.2, reversing at z ≳ 1.8, while star-forming galaxies (SFGs) show a mild positive correlation up to z ∼ 5.5. The specific SFR remains nearly flat for SFGs and declines with density for QGs at z ≲ 1.2. Moreover, mass and environmental quenching efficiencies show that mass-driven processes dominate at z ≳ 2.5, that the two processes act with comparable strength between 0.8 ≲ z ≲ 2.5, and that environmental quenching becomes stronger for low-mass galaxies (M_⋆ ≲ 10¹⁰M_⊙) at z ≲ 0.8. These findings reveal that large-scale structure drives galaxy evolution by enhancing early mass assembly in dense regions and increasingly suppressing star formation in low-mass systems at later times, establishing the environmental role of the cosmic web across cosmic history. COSMOS-Web, the largest JWST survey, provides accurate and deep photometric redshifts, reaching 80% mass completeness at logM⋆/M⊙∼8.7 at z ∼ 7, enabling the first view of how environments shaped galaxy evolution from the Epoch of Reionization to the present day.

Links

• ELECTR https://doi.org/10.3847/1538-4357/ae5bac
• PREPRINT http://arxiv.org/abs/2511.10727