The Galaxy Population In Voids: Are All Voids The Same?

TL;DR

This study examines how the properties of galaxies vary in different types of cosmic voids, revealing that void environment significantly influences galaxy mass, color, and luminosity distribution, with implications for understanding galaxy evolution.

Contribution

It introduces a classification of voids based on luminosity density contrast and analyzes how these environments affect galaxy properties, highlighting the importance of void environment in galaxy evolution.

Findings

Galaxies in sparse voids are less massive and bluer.

Luminosity function differs between sparse and populous voids.

Void environment impacts galaxy formation and evolution.

Abstract

The influence of under-dense environments on the formation and evolution of galaxies is studied by analysing the photometric properties of ~200 galaxies residing in voids, taken from our SDSS DR10 void catalogue up to z ~0.055. We split void galaxies into two subsamples based on the luminosity density contrast of their host voids: 'sparse void' {\delta}_s = {\delta} < -0.95 and 'populous void' {\delta}_p = {\delta} > -0.87. We find that galaxies in sparse voids are less massive than galaxies in populous voids. The luminosity distribution of galaxies in populous voids follows the same distribution observed across the SDSS survey in the same redshift range. Galaxies in the sparse voids are also bluer suggesting that they may be going through a relatively slow and continuous star formation. Additionally, we find that the luminosity function of galaxies in populous voids is represented with the Schechter function whereas the same does not hold for sparse voids. Our analysis suggests that the properties of a host void plays a significant role in the formation and evolution of the void galaxies and determining the large scale evolution of voids is an important step to understand what processes regulate the evolution of galaxies.