The Impact of ICM Substructure on Ram Pressure Stripping

TL;DR

This paper uses high-resolution cosmological simulations to study how substructure in the intracluster medium affects ram pressure stripping of galaxies, revealing significant variability in ram pressure due to ICM density and velocity differences.

Contribution

It demonstrates the impact of ICM substructure on ram pressure variability and the weak correlation between galaxy and ICM velocities during infall.

Findings

Ram pressure varies by over an order of magnitude at fixed cluster radius.

Variation is due equally to ICM density and relative velocity.

Weak correlation between galaxy and ICM velocities for infalling galaxies.

Abstract

Cluster galaxies moving through the intracluster medium (ICM) are expected to lose some of their interstellar medium (ISM) through ram pressure stripping and related ISM-ICM interactions. Using high-resolution cosmological simulations of a large galaxy cluster including star formation, we show that the ram pressure a galaxy experiences at a fixed distance from the cluster center can vary by well over an order of magnitude We find that this variation in ram pressure is due in almost equal parts to variation in the ICM density and in the relative velocity between the galaxy and the ICM. We also find that the ICM and galaxy velocities are weakly correlated for in-falling galaxies.