Filament profiles from WISExSCOS galaxies as probes of the impact of environmental effects

TL;DR

This study analyzes galaxy properties around cosmic filaments using WISExSCOS data, revealing gradients in star formation and galaxy types, and linking these to gas content and environmental effects in the Cosmic Web.

Contribution

It provides the first detailed profile of galaxy over-density and properties around filaments, incorporating gas pressure modeling to understand environmental influences.

Findings

Galaxy over-density radius ~7.5 Mpc

Passive galaxies are more concentrated near filament spines

Detected SFR and Mstar gradients towards filaments

Abstract

The role played by the large-scale structures in the galaxy evolution is not quite well understood yet. In this study, we investigate properties of galaxy in the range 0.1<z<0.3 from a value-added version of the WISExSCOS catalogue around cosmic filaments detected with DisPerSE. We have fitted a profile of galaxy over-density around cosmic filaments and found a typical radius of r_m = 7.5+-0.2 Mpc. We have measured an excess of passive galaxies near the filament's spine, higher than the excess of transitioning and active galaxies. We have also detected SFR and Mstar gradients pointing towards the filament's spine. We have investigated this result and found an Mstar gradient for each type of galaxies: active, transitioning, and passive, and a positive SFR gradient for passive galaxies. We also link the galaxy properties and the gas content in the Cosmic Web. To do so, we have investigated the quiescent fraction fQ profile of galaxies around the cosmic filaments. Based on recent studies about the effect of the gas and of the Cosmic Web on galaxy properties, we have modeled fQ with a beta model of gas pressure. The slope obtained here, beta=0.54+-0.18, is compatible with the scenario of projected isothermal gas in hydrostatic equilibrium (beta=2/3), and with the profiles of gas fitted in SZ.