Gas Stripping in Simulated Galaxies with a Multiphase ISM

TL;DR

This study uses high-resolution hydrodynamical simulations to analyze how a multiphase interstellar medium in galaxies is affected by ram pressure stripping in cluster environments, revealing differences in gas loss and morphology.

Contribution

It introduces detailed 3D simulations of multiphase ISM stripping, showing how high-density clouds behave differently during ram pressure interactions.

Findings

Gas loss is similar with or without cooling.

Multiphase ISM strips faster and to smaller radii.

High-density clouds can survive and migrate inward.

Abstract

Cluster galaxies moving through the intracluster medium (ICM) are expected to lose some of their interstellar medium (ISM) through ISM-ICM interactions. We perform high resolution (40 pc) three-dimensional hydrodynamical simulations of a galaxy undergoing ram pressure stripping including radiative cooling in order to investigate stripping of a multiphase medium. The clumpy, multiphase ISM is self-consistently produced by the inclusion of radiative cooling, and spans six orders of magnitude in gas density. We find no large variations in the amount of gas lost whether or not cooling is involved, although the gas in the multiphase galaxy is stripped more quickly and to a smaller radius. We also see significant differences in the morphology of the stripped disks. This occurs because the multiphase medium naturally includes high density clouds set inside regions of lower density. We find that the lower density gas is stripped quickly from any radius of the galaxy, and the higher density gas can then be ablated. If high density clouds survive, through interaction with the ICM they lose enough angular momentum to drift towards the center of the galaxy where they are no longer stripped. Finally, we find that low ram pressure values compress gas into high density clouds that could lead to enhanced star formation, while high ram pressure leads to a smaller amount of high-density gas.