The relationship between morphology, density and location in the cosmic web from massive to dwarf galaxies

We study how morphology relates to environment from massive to dwarf galaxies using, for the first time, a mass-complete sample of ~13,000 galaxies, in the stellar-mass and redshift ranges 108 M⊙ < M⋆ < 1011.5 M⊙ and 0.2 < z < 0.4, respectively. By combining HST-derived visual morphological classifications with local density and galaxy distances from nodes and filaments, we quantify how early-type and late-type galaxies (ETGs and LTGs) differ with respect to environment. The overall ETG fraction decreases from ~65 per cent at M⋆ ~ 1011 M⊙ to ~20 per cent at M⋆ ~ 108 M⊙. Regardless of morphology, lower stellar mass galaxies lie further away from nodes and filaments than their more massive counterparts. While, at M⋆ ≳ 109 M⊙, ETGs reside further away from nodes and filaments than LTGs, this segregation weakens as stellar mass decreases, with ETGs and LTGs exhibiting similar locations at M⋆ ≲ 109 M⊙. This diminishing difference at lower stellar mass is likely driven by the fact that filaments have a finite extent and lower stellar mass galaxies, of all morphologies, lie further away from filament cores and are therefore confined to a smaller region of the filament itself. For high-mass galaxies (where ETGs and LTGs show strong environmental segregation), greater proximity to nodes likely inhibits coherent angular momentum acquisition, while residing closer to filament cores increases the likelihood of interactions and mergers. Both make it easier to create dispersion-dominated systems, driving the sharp rise of the ETG fraction, in the high-mass regime, close to nodes (and, to a lesser extent) filaments. Our results show that galaxy evolution is increasingly driven by internal processes as stellar mass decreases.