The Effect of Environment on Galaxy Spiral Arms, Bars, Concentration, and Quenching

TL;DR

This study investigates how environment and star formation rate influence spiral arm properties in galaxies, finding that these properties are primarily linked to galaxy concentration and star formation, with minimal environmental impact.

Contribution

It extends previous Fourier analysis of galaxy structures by examining environmental effects and star formation, revealing that spiral arm features are mainly governed by galaxy concentration and sSFR.

Findings

No significant difference in spiral arm parameters between cluster and field galaxies when controlling for concentration.

Spiral arm strength and pitch angle correlate with specific star formation rate when concentration is fixed.

Relations support a 'fundamental plane' involving pitch angle, bulge mass, and gas density.

Abstract

For a sample of 4378 nearby spiral and S0 galaxies, Yu and Ho (2020) used Fourier analysis of Sloan Digital Sky Survey images to show that the strengths of the spiral arms and the pitch angles of the arms are inversely correlated with central concentration. In the current study, we search for trends in the Yu and Ho (2020) spiral arm parameters with environment and specific star formation rate (sSFR). When comparing galaxies with similar concentrations, we do not find a significant difference in the arm strengths or pitch angles of spiral galaxies in clusters compared to field galaxies. When differences in concentration are taken into account, we also find no significant difference in the parameter f3 for cluster spirals compared to field spirals, where f3 is the normalized m = 3 Fourier amplitude. When concentration is held fixed, both arm strength and pitch angle are correlated with sSFR, but f3 is not. These relations support the suggestion by Davis et al. (2015) of a `fundamental plane' of spiral structure involving pitch angle, bulge stellar mass, and gas surface density. We discuss these results in terms of theories of spiral arm production and quenching in galaxies. To aid comparison with earlier studies based on Galaxy Zoo, we explore how the Yu and Ho (2020) parameters relate to similar parameters measured by Galaxy Zoo (i.e., f3 vs. number of arms, pitch angle vs. winding parameter, and concentration vs. bulge class).