MUSE sneaks a peek at extreme ram-pressure stripping events -- V. Towards a complete view of the galaxy cluster A1367

TL;DR

This study uses integral field spectroscopy to analyze the kinematics and ionization in galaxies undergoing ram-pressure stripping in clusters, revealing shock signatures, star formation conditions, and stages of the stripping process.

Contribution

It provides a homogeneous analysis of ram-pressure stripping effects in multiple galaxies, highlighting ionization conditions, star formation triggers, and stages of gas removal.

Findings

Elevated [OI]/Hα ratios indicate shocks or turbulence in stripped gas tails.

Star formation in tails occurs only under specific, unknown conditions.

Different line ratios reveal stages of the stripping process and associated star formation activity.

Abstract

We present an analysis of the kinematics and ionization conditions in a sample composed of seven star-forming galaxies undergoing ram-pressure stripping in the A1367 cluster, and the galaxy ESO137-001 in the Norma cluster. MUSE observations of two new galaxies in this sample, CGCG097-073 and CGCG097-079, are also presented. This sample is characterized by homogeneous integral field spectroscopy with MUSE and by a consistent selection based on the presence of ionised gas tails. The ratio [OI]/H${\alpha}$ is consistently elevated in the tails of these objects compared to what observed in unperturbed galaxy disks, an ubiquitous feature which we attribute to shocks or turbulent phenomena in the stripped gas. Compact star-forming regions are observed in only $\approx$ 50% of the tails, implying that specific (currently unknown) conditions are needed to trigger star formation inside the stripped gas. Focusing on the interface regions between the interstellar and intracluster medium, we observe different line ratios that we associate to different stages of the stripping process, with galaxies at an early stage of perturbation showing more prominent signatures of elevated star formation. Our analysis thus demonstrates the power of a well selected and homogeneous sample to infer general properties arising from ram-pressure stripping inside local clusters.