Multivariate analysis of bar fractions in the local Universe

Abstract

This study presents a detailed investigation of bar abundances in present-day disk galaxies partitioned into morphological and activity classes. The relationship between bar fractions, and both the stellar mass and local environmental density of the galaxies has been examined using data from the literature that rely on two different bar identification procedures applied to objects extracted from two Sloan surveys, one based on SDSS and the other on MaNGA observations. Our study reveals that galaxies of all Hubble and BPT types show a more or less pronounced tendency to exhibit higher bar fractions with increasing stellar mass, being, respectively, the Sc and Seyfert galaxy classes the ones in which these transient structures are more abundant. We also detect two distinct regimes in the behaviour of the bar fraction with this parameter that, we speculate, could be related to the golden mass of galaxy formation. In contrast, the bar fraction is found to exhibit a weak or negligible dependence on the local baryon density. Although the results inferred from the two catalogues analysed show an overall consistency, there are some discrepancies in the behaviour of the predicted bar fractions, more obvious in the high-mass regime, that can hardly be explained unless there are hidden biases in the selection functions of the datasets