SIMBAD references

The relationship between galaxy properties and environment is a widely discussed topic within astrophysics. Here, we use galaxy samples from hydrodynamical resimulations to examine this relationship. We use the overdensity (δ₁) within a 1h^–1Mpc sphere around a galaxy to evaluate its environment. Then, the relations between galaxy properties, such as specific star formation rate (sSFR), fraction of star-forming galaxies, g - r color, and δ₁ are examined within three galactic samples formed from galaxies within large clusters, those in the vicinity of large clusters, and those in the field. We find tight environmental correlations for these galaxy properties. In brief, galaxies in denser environments tend to be redder and are more likely to be quenched; this is consistent with observations. We find that although the sSFR decreases with δ₁, this is mainly because galaxies with higher stellar mass reside in an environment with higher overdensity. At fixed overdensity, a galaxy's color is also independent of whether it lives within a cluster or within the field, but the relative fractions of the two samples varies dramatically with overdensity, and this drives an apparent evolution.