The Fundamental Plane Relation of Early-Type Galaxies: Environmental Dependence

TL;DR

This study investigates how the fundamental plane relation of early-type galaxies varies with environment, revealing distinct behaviors for central and satellite galaxies across different halo masses.

Contribution

It provides the first detailed analysis of environmental dependence of the fundamental plane for a large galaxy sample, highlighting differences between centrals and satellites.

Findings

Centrals' fundamental plane coefficients vary with halo mass.

Satellites' coefficients are consistent across halo masses.

Environmental effects are more pronounced in small halos.

Abstract

Using a sample of 70,793 early-type galaxies from SDSS DR7, we study the environmental dependence of the fundamental plane relation. With the help of the galaxy group catalogue based on SDSS DR7, we calculate the fundamental planes in different dark matter halo mass bins for central and satellite galaxies respectively. We find the environmental dependence of the fundamental plane coefficients are similar in $g$, $r$, $i$ and $z$ bands. The environmental dependence for central and satellite galaxies is significantly different. While the fundamental plane coefficients of centrals vary systematically with the halo mass, those of satellites are similar in different halo mass bins. The discrepancy between centrals and satellites are significant in small halos, but negligible in the largest halo mass bins. These results remain the same when we only keep red galaxies, or galaxies with $b/a>0.6$, or galaxies in a specific radius range in the sample. After the correction of the sky background, results are still similar. We suggest that the different environmental effects of the halo mass on centrals and satellites may arise from the different quenching processes of them.