Dynamical Influence of Bars on the Star Formation in Isolated Galaxies

TL;DR

This study investigates how bars influence star formation in isolated spiral galaxies by analyzing Halpha emission and gravitational torques, revealing the dynamical impact of bars on star-forming regions.

Contribution

It provides a detailed analysis of the dynamical influence of bars on star formation in isolated galaxies using Fourier analysis and torque measurements.

Findings

Bars significantly affect the distribution of star formation.

Gravitational torques correlate with Halpha emission patterns.

Isolated galaxies show diverse bar strengths and star formation responses.

Abstract

Star formation depends strongly on both the local environment of galaxies and the internal dynamics of the interstellar medium. To disentangle the two effects, we obtained, in the framework of the AMIGA project, Halpha and Gunn r photometric data for more than 200 spiral galaxies lying in very low-density regions of the local Universe. We characterise the Halpha emission, tracing current star formation, of the 45 largest and least inclined galaxies observed for which we estimate the torques between the gas and the bulk of the optical matter. We subsequently study the Halpha morphological aspect of these isolated spiral galaxies. Using Fourier analysis, we focus on the modes of the spiral arms and also on the strength of the bars, computing the torques between the gas and newly formed stars (Halpha), and the bulk of the optical matter (Gunn r).