From Feast To Famine: the Role of HI in Group Evolution

TL;DR

This paper discusses how sensitive MeerKAT radio observations can reveal the role of intragroup gas in galaxy evolution, particularly in the transition from star-forming to quenched states within galaxy groups.

Contribution

It highlights the potential of MeerKAT's capabilities to study intragroup gas and its influence on galaxy evolution, addressing observational challenges in this field.

Findings

MeerKAT's design enables detection of diffuse intragroup gas.

Intragroup gas plays a significant role in galaxy quenching.

Multiwavelength data combined with HI observations enhances understanding of galaxy transformation.

Abstract

Galaxies in the local universe are most commonly found in groups and are thought to be "pre-processed" in this environment before being consumed by clusters. Yet we know very little about the gastrophysics of these systems, how they evolve and how this environment is connected to the quenching of star-forming galaxies. In particular, the role of intragroup gas has been challenging to uncover due to observational constraints and the limitations of radio telescopes to date. Sensitive, interferometric \HI\ observations of galaxy groups, combined with multiwavelength tracers of stellar mass, star formation and shocks, is necessary to examine the physical processes transforming galaxies from star-forming to quenched. These laboratories may be key to understanding the dominant mechanisms driving galaxy evolution. MeerKAT uniquely combines a large field of view, column density sensitivity, and excellent UV coverage on short baselines ensuring sensitivity to diffuse gas. This design makes it a compelling instrument for the study of intragroup and circumgroup gas, quenching in galaxy groups, and for tracing evolutionary pathways within the group environment.