Bar likelihood in local galaxies: the joint role of stellar mass, morphology and environment

We investigate how the likelihood of hosting a stellar bar depends on both intrinsic galaxy properties and environment, using a volume-limited sample of central and satellite galaxies from the NASA–Sloan Atlas, spanning isolated systems, low- and high-richness groups, and massive haloes, complemented with halo-based environmental information and probabilistic morphology. Using probabilistic bar identification, we quantify the bar likelihood as a function of stellar mass, colour, morphology, halo mass, and cluster-centric distance. We find that stellar mass and morphology are the galaxy properties most associated with the bar likelihood. At fixed morphology, the probability of hosting a bar increases with stellar mass, particularly for late-type galaxies. At the same time, morphology strongly modulates the overall incidence of bars, with early-type galaxies displaying systematically lower probabilities than late-type systems across the stellar mass range. Environmental trends are observed, including halo mass and cluster-centric distance, but these trends largely reflect the morphological composition of the galaxy population. In particular, the decrease in bar likelihood towards the centres of massive haloes reflects the increasing fraction of early-type galaxies, consistent with the morphology–density relation, rather than a direct environmental suppression of bars. Our residual analysis finds no statistically significant residual dependence on halo mass or normalized cluster-centric distance after accounting for stellar mass and morphology, within the sensitivity of this sample. Overall, our results show that stellar mass and morphology are the main factors associated with bar likelihood, while environmental trends largely reflect morphological composition.