Evidence for mixing between ICM and stripped ISM by the analysis of the gas metallicity in the tails of jellyfish galaxies

TL;DR

This study uses MUSE observations of jellyfish galaxies to analyze gas metallicity in their tails, providing evidence for mixing between the interstellar medium and intracluster medium, consistent with hydrodynamical simulations.

Contribution

It offers observational evidence of ICM and ISM mixing in galaxy tails, supporting simulation predictions with metallicity profiles.

Findings

Metallicity decreases with distance from galaxy disks.

Over 40% of metal-poor clouds are cooled ICM.

Observations align with hydrodynamical simulation predictions.

Abstract

Hydrodynamical simulations show that the ram-pressure stripping in galaxy clusters fosters a strong interaction between stripped interstellar medium (ISM) and the surrounding medium, with the possibility of intracluster medium (ICM) cooling into cold gas clouds. Exploiting the MUSE observation of three jellyfish galaxies from the GAs Stripping Phenomena in galaxies with MUSE (GASP) survey, we explore the gas metallicity of star-forming clumps in their gas tails. We find that the oxygen abundance of the stripped gas decreases as a function of the distance from the parent galaxy disk; the observed metallicity profiles indicate that more than 40% of the most metal-poor stripped clouds are constituted by cooled ICM, in qualitative agreement with simulations that predict mixing between the metal-rich ISM and the metal-poor ICM.