A phase-space view of cold-gas properties of Virgo-cluster galaxies: multiple quenching processes at work?

TL;DR

This study analyzes Virgo cluster galaxies' cold-gas properties using phase-space diagrams, revealing environmental effects like gas stripping and strangulation influencing galaxy evolution at various cluster radii.

Contribution

It provides the largest archival dataset to date for Virgo galaxies, showing environmental impacts on cold-gas content and star formation efficiency at different cluster locations.

Findings

Virgo galaxies have lower HI and H₂ mass fractions than field galaxies.

Gas fractions decrease closer to the cluster center and in substructures.

Some galaxies show signs of ram pressure stripping and strangulation effects.

Abstract

We investigate the cold-gas properties of massive Virgo galaxies ($>10^9$ M$_\odot$) at $<3R_{200}$ ($R_{200}$ is the radius where the mean interior density is 200 times the critical density) on the projected phase-space diagram (PSD) with the largest archival dataset to date to understand the environmental effect on galaxy evolution in the Virgo cluster. We find: lower HI and H$_2$ mass fractions and higher star-formation efficiencies (SFEs) from HI and H$_2$ in the Virgo galaxies than the field galaxies for matched stellar masses; the Virgo galaxies generally follow the field relationships between the offset from the main sequence of the star-forming galaxies [$\Delta$(MS)] with gas fractions and SFEs but slightly offset to lower gas fractions or higher SFEs than field galaxies at $\Delta({\rm MS})< 0$; lower gas fractions in galaxies with smaller clustocentric distance and velocity; lower gas fractions in the galaxies in the W cloud, a substructure of the Virgo cluster. Our results suggest the cold-gas properties of some Virgo galaxies are affected by their environment at least at $3 R_{200}$ maybe via strangulation and/or pre-processes and HI and H$_2$ in some galaxies are removed by ram pressure at $<1.5 R_{200}$. Our data cannot rule the possibility of the other processes such as strangulation and galaxy harassment accounting for the gas reduction in some galaxies at $<1.5 R_{200}$. Future dedicated observations of a mass-limited complete sample are required for definitive conclusions.