Strong Bars, Strong Inflow: The Effect of Bar Strength on Gas Inflow
Abstract
Stellar bars are elongated structures in disk galaxies that can torque and funnel gas inward, influencing galaxy evolution. While strong bars are known to induce rapid inflow, the impact of weaker bars remains less certain. We collected spectroscopic data using the Isaac Newton Telescope to analyze 18 nearby galaxies (strongly barred, weakly barred, and unbarred) drawn from Galaxy Zoo DESI. We obtained spatial profiles of equivalent width (EW) and ionized gas velocity dispersion by fitting Gaussian profiles to the H{\alpha} emission line. Strongly barred galaxies exhibit a distinctive three-peaked EW[H{\alpha}] structure, consistent with inward funneling of gas. Weakly barred systems lack this pattern, which suggests limited inflow. Velocity dispersion distributions further distinguish the bar types, with strongly barred galaxies showing significantly higher values than weakly barred and unbarred systems. These results suggest that strong bars drive gas inflow, while weak bars exert a limited dynamical influence.
Cite
@article{arxiv.2512.10164,
title = {Strong Bars, Strong Inflow: The Effect of Bar Strength on Gas Inflow},
author = {Maelle Magnan and Tobias Geron and Izzy L. Garland and Chris J. Lintott and Jason Shingirai Makechemu and David O Ryan and Brooke D. Simmons and Rebecca J. Smethurst},
journal= {arXiv preprint arXiv:2512.10164},
year = {2025}
}