# Galaxy And Mass Assembly (GAMA): Environmental Quenching of Centrals and Satellites in Groups

## TL;DR

This study investigates how galaxy quenching depends on environment and galaxy status, revealing differences between centrals and satellites and emphasizing the importance of group properties in quenching processes.

## Contribution

It demonstrates that passive fractions differ between centrals and satellites when carefully analyzed, highlighting the role of halo and group properties in environmental quenching.

## Key findings

- Passive fractions increase with halo-to-satellite mass ratio.
- Passive fractions are higher in older, more evolved groups.
- Differences between centrals and satellites depend on group-finding methods.

## Abstract

Recently a number of studies have found a similarity between the passive fraction of central and satellite galaxies when controlled for both stellar and halo mass. These results suggest that the quenching processes that affect galaxies are largely agnostic to central/satellite status, which contradicts the traditional picture of increased satellite quenching via environmental processes such as stripping, strangulation and starvation. Here we explore this further using the Galaxy And Mass Assembly (GAMA) survey which extends to ~2dex lower in stellar mass than SDSS, is more complete for closely-separated galaxies (>95% compared to >70%), and identifies lower-halo-mass groups outside of the very local Universe (M$_{\mathrm{halo}}\sim10^{12}$M$_{\odot}$ at $0.1<z<0.2$). As far as possible we aim to replicate the selections, completeness corrections and central/satellite division of one of the previous studies but find clear differences between passive fractions of centrals and satellites. We also find that our passive fractions increase with both halo-to-satellite mass ratio and central-to-second rank mass ratio. This suggests that quenching is more efficient in satellites that are low-mass for their halo ($i.e$ at high halo-to-satellite mass ratio in comparison to low halo-to-satellite mass ratio) and are more likely to be passive in older groups - forming a consistent picture of environmental quenching of satellites. We then discuss potential explanations for the previously observed similarity, such as dependence on the group-finding method.