A universal correlation between warm and hot gas in the stripped tails of cluster galaxies

TL;DR

This study uncovers a universal linear correlation between X-ray and Hα surface brightness in the multi-phase tails of stripped cluster galaxies, revealing insights into gas mixing and energy transfer processes in galaxy clusters.

Contribution

It demonstrates a strong linear correlation between X-ray and Hα emissions in galaxy tails, providing new evidence for gas mixing and energy transfer mechanisms in multi-phase environments.

Findings

Linear correlation between X-ray and Hα surface brightness with a slope of ~3.5

Evidence for mixing of interstellar and intracluster medium in galaxy tails

Implications for models of energy transfer in multi-phase gas

Abstract

The impact of ram pressure stripping on galaxy evolution is well known. Recent multi-wavelength data have revealed many examples of galaxies undergoing stripping, often accompanied with multi-phase tails. As energy transfer in the multi-phase medium is an outstanding question in astrophysics, galaxies in stripping are great objects to study. Despite the recent burst of observational evidence, the relationship between gas in different phases in the tails is poorly known. Here we report a strong linear correlation between the X-ray surface brightness and the H$\alpha$ surface brightness of the diffuse gas in the stripped tails at $\sim$ 10 - 40 kpc scales, with a slope of $\sim$ 3.5. This discovery provides evidence for the mixing of the stripped interstellar medium with the hot intracluster medium as the origin of the multi-phase tails. The established relation in stripped tails, also in comparison with the likely related correlations in similar environments like galactic winds and X-ray cool cores, provides an important test for models of energy transfer in the multi-phase gas. It also indicates the importance of the H$\alpha$ data to study clumping and turbulence in the intracluster medium.