UV-IR luminosity functions and stellar mass functions of galaxies in the Shapley supercluster core

TL;DR

This study analyzes galaxy luminosity and stellar mass functions in the Shapley supercluster core, revealing environment-dependent star formation suppression but stable stellar mass distributions, indicating quenching processes dominate over mass loss.

Contribution

It provides new insights into how dense environments influence galaxy properties, showing that star formation is quenched without significant stellar mass loss.

Findings

Faint-end slopes of optical and NIR LFs steepen in lower-density regions.

SMFs show no significant environmental dependence in their slopes.

UV LFs are steeper than in the local field, IR LFs are consistent with the field.

Abstract

We present a panchromatic study of luminosity functions (LFs) and stellar mass functions (SMFs) of galaxies in the core of the Shapley supercluster at z=0.048, in order to investigate how the dense environment affects the galaxy properties, such as star formation (SF) or stellar masses. We find that while faint-end slopes of optical and NIR LFs steepen with decreasing density, no environment effect is found in the slope of the SMFs. This suggests that mechanisms transforming galaxies in different environments are mainly related to the quench of SF rather than to mass-loss. The Near-UV (NUV) and Far-UV (FUV) LFs obtained have steeper faint-end slopes than the local field population, while the 24$\mu$m and 70$\mu$m galaxy LFs for the Shapley supercluster have shapes fully consistent with those obtained for the local field galaxy population. This apparent lack of environmental dependence for the infrared (IR) LFs suggests that the bulk of the star-forming galaxies that make up the observed cluster IR LF have been recently accreted from the field and have yet to have their SF activity significantly affected by the cluster environment.