The Evolution of Galaxy Disks in Dense Environments - Lessons from Compact Galaxy Groups

TL;DR

This study investigates the causes of HI deficiency in disk galaxies within compact groups, exploring various environmental processes and highlighting the complexity of ISM evolution in dense galaxy environments.

Contribution

It provides the first multi-wavelength analysis of HI deficiency in compact galaxy groups, evaluating multiple mechanisms and discussing future research directions.

Findings

Tidal and ram pressure stripping, star-formation strangulation may influence HI content.

No single process fully explains the HI deficiency across the sample.

Further multi-wavelength studies are needed to understand ISM evolution.

Abstract

Disk galaxies in compact galaxy groups exhibit a remarkable shortfall of neutral hydrogen compared to both isolated spirals and spirals in more loose groups, but the origin of this HI deficiency remains unclear. Based on a sample of highly HI deficient compact galaxy groups, here updated to also include HCG 58 and HCG 93, we summarise the first results of a multi-wavelength campaign aimed at understanding the processes responsible for modifying the HI content of galaxy disks in these environments. While tidal stripping, ram pressure stripping by hot intragroup gas, and star-formation induced strangulation could individually be affecting the ISM in some of the group members, these processes each face specific difficulties in explaining the inferred deficiency of HI for the sample as a whole. A complete picture of the mechanisms driving the ISM evolution in the disk galaxies of these groups has thus yet to emerge, but promising avenues for further progress in this field are briefly discussed on the basis of the present sample.