Galaxies evolve during their journey towards the cosmic web from low density to high density environments. As environment gets denser, galaxies are less efficient at forming new stars and become quiescent.
Galaxies in (nearby) clusters are subject to (i) gravitational interactions with other galaxies and with the cluster potential well, leading to mergers, tidal stripping, and harassment; (ii) hydrodynamical interactions between their cold gas and the hot intra-group/cluster medium, inducing ram-pressure stripping; and (iii) other mechanisms like starvation, strangulation, etc. It is observed that galaxy properties begin to change before entering the densest structures, the red sequence gradually forming as the environment gets denser. Pre-processing occurring while galaxies migrate from low- to high-density regions of the cosmic web (voids, walls, filaments, groups, and clusters) may be responsible for this and may have started at intermediate to high redshifts, when structures start to form and star-formation is still high.

What are the main gas stripping mechanisms at intermediate redshifts?
One first aspect of this project is to quantify the mechanisms responsible for gas stripping in intermediate galaxies in dense groups using MUSE, HST and JWST of the MAGIC sample, by comparing the distribution of ionized gas and of stars. Systematic offsets as well as smaller gaseous disks could be indicative of ram-pressure stripping being the dominating mechanisms. We aim at quantifying the fraction of galaxies showing gravitation interactions (e.g. tidal tails and mergers) as well as extended emission.

How and when environment impacts star-formation efficiency?
Besides this approach, the project aim at understanding when and how environment quench the star-formation efficiency by comparing the molecular gas fraction and spatial distribution between field, group and cluster galaxies, and to follow these properties with redshift. We more specifically want to study the link between star formation rate, molecular gas content and molecular gas extent for galaxies involved in ram pressure events and gravitational interactions leading to extended ionized gas emission.

What are the ionization conditions in stripping tails and what their kinematics tell us about the striping history?
Another goal of the project is to study in detail the kinematics and ionization conditions of tidal interaction tails and ram pressure stripping tails in local Universe cluster galaxies, using integral field spectroscopy, and to compare them to extended tails at higher redshifts.

The longer term objective is to get prepared for future generations of telescopes in the visible, infra-red (ELT, WST) and in radio wavelengths (SKA, next-generation ALMA observatory) that will nicely complement our vision of galaxy pre-processing as they reach denser environments.