SDSS-IV MaNGA: The link between bars and the early cessation of star formation in spiral galaxies

TL;DR

This study analyzes how bars in spiral galaxies influence their star formation histories, finding that barred galaxies tend to be older, more metal-rich, and have ceased star formation earlier than unbarred ones, especially in high-mass systems.

Contribution

It provides the first comprehensive comparison of stellar populations and gas content between barred and unbarred galaxies using MaNGA data, highlighting the link between bars and galaxy quenching.

Findings

Barred galaxies are optically redder and more metal-rich.

Star formation peaks earlier in barred galaxies.

High-mass barred galaxies have lower HI gas fractions.

Abstract

Bars are common in low-redshift disk galaxies, and hence quantifying their influence on their host is of importance to the field of galaxy evolution. We determine the stellar populations and star formation histories of 245 barred galaxies from the MaNGA galaxy survey, and compare them to a mass- and morphology-matched comparison sample of unbarred galaxies. At fixed stellar mass and morphology, barred galaxies are optically redder than their unbarred counterparts. From stellar population analysis using the full spectral fitting code Starlight, we attribute this difference to both older and more metal-rich stellar populations. Dust attenuation however, is lower in the barred sample. The star formation histories of barred galaxies peak earlier than their non-barred counterparts, and the galaxies build up their mass at earlier times. We can detect no significant differences in the local environment of barred and un-barred galaxies in this sample, but find that the HI gas mass fraction is significantly lower in high-mass ($\rm{M}_{\star} > 10^{10}~\rm{M}_{\odot}$) barred galaxies than their non-barred counterparts. We speculate on the mechanisms that have allowed barred galaxies to be older, more metal-rich and more gas-poor today, including the efficient redistribution of galactic fountain byproducts, and a runaway bar formation scenario in gas-poor disks. While it is not possible to fully determine the effect of the bar on galaxy quenching, we conclude that the presence of a bar and the early cessation of star formation within a galaxy are intimately linked.