SDSS-IV MaNGA: Spatially resolved star formation in barred galaxies

TL;DR

This study uses the MaNGA survey to analyze how bars in disk galaxies influence star formation, revealing that star formation along bars occurs mainly in low-mass galaxies and is affected by galaxy properties.

Contribution

It provides a comprehensive analysis of star formation in barred galaxies across various masses and environments, highlighting the role of bars in galaxy evolution.

Findings

Star formation along bars is present only in low-mass galaxies.

Star formation at bar ends is predominantly at the leading edge.

Bar properties are mainly influenced by the host galaxy's stellar mass.

Abstract

Bars inhabit the majority of local-Universe disk galaxies and may be important drivers of galaxy evolution through the redistribution of gas and angular momentum within disks. We investigate the star formation and gas properties of bars in galaxies spanning a wide range of masses, environments, and star formation rates using the MaNGA galaxy survey. Using a robustly-defined sample of 684 barred galaxies, we find that fractional (or scaled) bar length correlates with the host's offset from the star-formation main sequence. Considering the morphology of the H$\alpha$ emission we separate barred galaxies into different categories, including barred, ringed, and central configurations, together with H$\alpha$ detected at the ends of a bar. We find that only low-mass galaxies host star formation along their bars, and that this is located predominantly at the leading edge of the bar itself. Our results are supported by recent simulations of massive galaxies, which show that the position of star formation within a bar is regulated by a combination of shear forces, turbulence and gas flows. We conclude that the physical properties of a bar are mostly governed by the existing stellar mass of the host galaxy, but that they also play an important role in the galaxy's ongoing star formation.