COSMOS-Web Releases 780,000-Galaxy Morphology Catalog Revealing Mass-Dependent Structural Evolution to z~6

The catalog applies uniform parametric and non-parametric fits independently in each band to the COSMOS2025 parent sample. This yields Sérsic indices, bulge-to-total ratios, and asymmetry-concentration diagnostics that trace the same galaxies from rest-UV through rest-optical wavelengths. The approach directly links structural parameters to the star-formation main sequence at 0<z<4, exposing how bulge growth tracks quenching across cosmic time.

Median n_sersic for galaxies above 10^10.5 solar masses rises from 1 at z6 to 2.5 at z2 while lower-mass systems remain disk-dominated. UV indices are systematically lower than optical values, consistent with inside-out growth and dust-obscured central star formation. These trends align with earlier HST-based results from CANDELS yet extend them by two magnitudes in depth and a factor of three in sample size.

The release enables direct cross-matching with ALMA continuum and Chandra X-ray catalogs already in COSMOS, a step the abstract does not emphasize. Such multi-wavelength overlays will test whether morphological quenching precedes or follows black-hole feedback signatures. Follow-up IFU observations with JWST or ELT will be required to confirm kinematic bulge fractions.

Next analyses will quantify the redshift-dependent scatter in the n_sersic–B/T relation and search for morphological signatures of mergers versus secular processes at fixed stellar mass.