Distribution of satellite galaxies in high redshift groups

TL;DR

This study analyzes the distribution, color, morphology, and alignment of satellite galaxies in high-redshift groups, revealing bimodal properties, morphological conformity, and weak alignment signals that inform galaxy group evolution.

Contribution

It provides new insights into the color-morphological bimodality, conformity, and alignment of satellite galaxies at high redshift, using GOODS survey data.

Findings

Red and blue satellite galaxies correspond to early and late morphological types.

Early-type satellites are generally brighter than late-type ones.

There is a morphological conformity between central and satellite galaxies.

Abstract

We use galaxy groups at redshifts between 0.4 and 1.0 selected from the Great Observatories Origins Deep Survey (GOODS) to study the color-morphological properties of satellite galaxies, and investigate possible alignment between the distribution of the satellites and the orientation of their central galaxy. We confirm the bimodal color and morphological type distribution for satellite galaxies at this redshift range: the red and blue classes corresponds to the early and late morphological types respectively, and the early-type satellites are on average brighter than the late-type ones. Furthermore, there is a {\it morphological conformity} between the central and satellite galaxies: the fraction of early-type satellites in groups with an early-type central is higher than those with a late-type central galaxy. This effect is stronger at smaller separations from the central galaxy. We find a marginally significant signal of alignment between the major axis of the early-type central galaxy and its satellite system, while for the late-type centrals no significant alignment signal is found. We discuss the alignment signal in the context of shape evolution of groups.