The Role of Dynamical Equilibrium Pressure in the Different Molecular Gas Ratios and Star Formation Properties of Cluster Galaxies and Field Galaxies

Abstract

The environment of a galaxy influences its gas and star formation properties via evolutionary mechanisms, such as ram pressure stripping and tidal stripping. In particular, the molecular to atomic gas ratio and dynamical equilibrium pressure are key parameters for understanding star formation in galaxies. I use 1.2 kpc resolution data for galaxies in the Virgo Cluster from the VERTICO survey and for field galaxies from the HERACLES survey to study the spatially resolved relationship between molecular to atomic gas ratios and star formation properties (eg. star formation rate, molecular gas depletion time) in galaxies as a function of dynamical equilibrium pressure. I find that cluster galaxies have higher molecular to atomic gas ratios at a given dynamical equilibrium pressure than field galaxies do. Within both samples there is strong galaxy to galaxy variation in the relationship driven by the gas content of each galaxy. In order to investigate the role of cluster environmental mechanisms on the properties of cluster galaxies I use atomic gas deficiency as a proxy for these environmental mechanisms. I find that atomic gas deficiency plays a significant role in the gas properties, star formation properties and dynamical equilibrium pressure of cluster galaxies.