Stellar, gas and dark matter content of barred galaxies

TL;DR

This study investigates the relationship between bars in galaxies and their stellar, gas, and dark matter content, revealing that bar presence correlates with stellar mass and inversely with gas richness and halo mass.

Contribution

It provides new insights into how stellar, gas, and dark matter components influence bar formation and prevalence in galaxies, using SDSS and ALFALFA data.

Findings

Bar fraction increases with stellar mass

Bar fraction decreases with gas mass fraction

Bar presence declines with increasing halo mass in massive galaxies

Abstract

We select a sample of galaxies from the Sloan Digital Sky Survey Data Release 7 (SDSS-DR7) where galaxies are classified, through visual inspection, as hosting strong bars, weak bars or as unbarred galaxies, and make use of HI mass and kinematic information from the Arecibo Legacy Fast ALFA (ALFALFA) survey catalog, to study the stellar, atomic gas and dark matter content of barred disk galaxies. We find, in agreement with previous studies, that the bar fraction increases with increasing stellar mass. A similar trend is found with total baryonic mass, although the dependence is not as strong as with stellar mass, this due to the contribution of gas. The bar fraction shows a decrease with increasing gas mass fraction. This anticorrelation between the likelihood of a galaxy hosting a bar with the gas richness of the galaxy results from the inhibiting effect the gas has in the formation of bars. We also find that for massive galaxies with stellar masses larger than 10$^{10} M_{\odot}$, at fixed stellar mass, the bar fraction decreases with increasing global halo mass (i.e. halo mass measured up to a radius of the order of the HI disk extent).