The relation between morphology, star formation history, and environment in local universe galaxies

TL;DR

This study investigates how local and large-scale environments influence galaxy morphology and star formation, finding local effects are more significant and that morphology is crucial for understanding galaxy evolution in clusters.

Contribution

The paper provides a detailed analysis of environmental impacts on galaxy evolution, emphasizing the dominant role of local effects over large-scale environment and the importance of morphology.

Findings

Local environment has a stronger impact on star formation than large-scale environment.

Morphology is essential to understand the mechanisms driving galaxy evolution.

Local density and cluster proximity significantly influence galaxy properties.

Abstract

The observed properties of galaxies are strongly dependent on both their total stellar mass and their morphology. Furthermore, the environment is known to play a strong role in shaping them. The galaxy population in the local universe that is located in virialized clusters is found to be red, poorly star-forming, and mostly composed of early morphological types. Towards a holistic understanding of the mechanisms that drive galaxy evolution, we exploit the spectrophotometric data from the WINGS and OmegaWINGS local galaxy cluster surveys, and study the role of both the local and the large-scale environments. We attempt to disentangle their effects from the intrinsic characteristics of the galaxies, in shaping the star formation activity at fixed morphological type and stellar mass. Using a sample of field galaxies from the same surveys for comparison, we analyse the effects of the environment, embodied by the local density, clustercentric distance, and close neighbours, respectively, on the star formation histories of cluster galaxies. We find that local effects have a more relevant impact on galaxy stellar properties than the large-scale environment, and that morphology needs to be taken into account to pinpoint the mechanisms that are driving the influence of clusters in galaxy evolution.