VERTICO II: effects of HI-identified environmental mechanisms on molecular gas

TL;DR

This study investigates how environmental effects identified through HI observations influence the molecular gas in Virgo cluster galaxies, revealing that HI deficiency correlates with truncated molecular gas profiles and moderate molecular gas reduction.

Contribution

It provides detailed analysis of molecular gas properties in cluster galaxies, linking HI-identified environmental mechanisms to molecular gas distribution and content.

Findings

HI deficiency correlates with steeper molecular gas profiles

Environmental mechanisms affect molecular gas distribution

Moderate reduction in total molecular gas in affected galaxies

Abstract

In this VERTICO early science paper we explore in detail how environmental mechanisms, identified in HI, affect the resolved properties of molecular gas reservoirs in cluster galaxies. The molecular gas is probed using ALMA ACA (+TP) observations of 12CO(2-1) in 51 spiral galaxies in the Virgo cluster (of which 49 are detected), all of which are included in the VIVA HI survey. The sample spans a stellar mass range of 9 < log M*/Msol < 11. We study molecular gas radial profiles, isodensity radii, and surface densities as a function of galaxy HI deficiency and morphology. There is a weak correlation between global HI and H2 deficiencies, and resolved properties of molecular gas correlate with HI deficiency: galaxies that have large HI deficiencies have relatively steep and truncated molecular gas radial profiles, which is due to the removal of low-surface density molecular gas on the outskirts. Therefore, while the environmental mechanisms observed in HI also affect molecular gas reservoirs, there is only a moderate reduction of the total amount of molecular gas.