Study of galaxies on large-scale filaments in simulations

TL;DR

This study uses cosmological simulations to analyze how galaxy properties vary within large-scale cosmic filaments, revealing environmental effects on star formation, gas content, and galaxy interactions.

Contribution

It provides new insights into the environmental dependence of galaxy evolution within cosmic web filaments using simulation data.

Findings

Galaxies closer to filament spines are redder and have lower star formation rates.

Gas and stellar mass fractions increase sharply near filament spines.

Proximity to filament centers enhances gravitational interactions among galaxies.

Abstract

We use data from the Evolution and Assembly of GaLaxies in their Environment (EAGLE) cosmological simulation to study properties of galaxies in the cosmic web. Galaxies become more redder and form stars at a lower rate relative to their counterparts further away from the cylindrical axis of the large-scale filaments. These trends are particularly strong for galaxies with $M_*/M_{\odot}\lesssim10^{10}$. We also find that at distances $<0.5$ Mpc from the spine of the filaments, the median gas and stellar mass fraction in filament galaxies rises sharply with decreasing distance from the spine of the filament. These results, together with matching trends in the SFR/$M_*$ and the $g-r$ colour of filament galaxies suggest that (i) the intrafilamentary gas condenses into the filament galaxies thus fuelling star formation in them, and (ii) increased number density of galaxies closer to the central axis of the filament enhances the rate of gravitational interactions among filament galaxies closer to the spine.