Dependence of Nebular Heavy-Element Abundance on H I Content for Spiral Galaxies

TL;DR

This study finds a universal positive correlation between H I deficiency and nebular metallicity in spiral galaxies across different environments, suggesting metal-poor inflows influence galaxy evolution.

Contribution

It demonstrates for the first time that field spiral galaxies show a similar H I deficiency-metallicity dependence as cluster galaxies, indicating a universal process.

Findings

Positive correlation between H I deficiency and metallicity in cluster galaxies.

Field galaxies also follow the same metallicity-H I deficiency trend.

Results align with cosmological simulations including inflows and outflows.

Abstract

We analyze the galactic H I content and nebular log(O/H) for 60 spiral galaxies in the Moustakas et al. (2006) spectral catalog. After correcting for the mass-metallicity relationship, we show that the spirals in cluster environments show a positive correlation for log(O/H) on DEF, the galactic H I deficiency parameter, extending the results of previous analyses of the Virgo and Pegasus I clusters. Additionally, we show for the first time that galaxies in the field obey a similar dependence. The observed relationship between H I deficiency and galactic metallicity resembles similar trends shown by cosmological simulations of galaxy formation including inflows and outflows. These results indicate the previously observed metallicity-DEF correlation has a more universal interpretation than simply a cluster's effects on its member galaxies. Rather, we observe in all environments the stochastic effects of metal-poor infall as minor mergers and accretion help to build giant spirals.