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

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 $\Delta (\mathrm{MS})<0$; 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 $3R_{200}$ maybe via strangulation and/or pre-processes and HI and H${}_2$ in some galaxies are removed by ram pressure at $<1.5R_{200}$. 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 $<1.5R_{200}$. Future dedicated observations of a mass-limited complete sample are required for definitive conclusions.

32 pages, 16 figures, accepted for publication in ApJ; Updated stellar masses of galaxies after the first acceptance, relevant texts, and figures