Leader: Oguzhan Cakir
Email: oguzhan.cakir@students.mq.edu.au
Collaborators: Matt Owers, Mina Pak, Gabriella Quattropani, and anyone who wants to collaborate
Topic: The future fate of ram-pressure affected cluster galaxies
Status: under review by Science Committee
Abstract: The environmental conditions found in galaxy clusters are efficient in quenching the star formation activity of resident galaxies. Yet, there is no clear understanding of the interplay between the cluster’s dynamical state and the properties of galaxies. The cluster mergers disturb the intra-cluster medium (ICM) due to high relative speeds and shocks – leading to a pressure jump in the ICM. These features may amplify the ram pressure felt by cluster galaxies. All things considered, hosting a more extreme environment, the cluster mergers may expectedly present a higher incidence of galaxies affected by ram pressure. Therefore, the identification of these objects and determining the incidence across a sample of clusters with varying merger phases is essential to disentangle the impact of different merger phases on the galaxy properties. In this study, we aim to identify the cluster galaxies affected by ram pressure stripping (RPS) in two clusters being at the different merger phases from the HECTOR cluster sample – A3716 is pre-merger and A3667 is close to the core-passage phase. The first data release provides 466 cluster galaxies for these systems. Using both visual classification and a quantitative assessment of the concentration and asymmetry of the ionized gas distribution, we search for direct evidence of RPS in the forms of asymmetric one-sided tails or truncation in their ionized gas relative to the stellar continuum. Following the identification step, we then run a comparative analysis to investigate the relative incidence of RPS-affected galaxies in these clusters – which can be compared to the more relaxed A85/A119 clusters with similar masses by exploiting the SAMI data. Considering the larger coverage up to 2R200 where both the first infallers and the backsplash galaxies can be found, HECTOR will allow us to study the environment-driven evolution of galaxies by providing a complete picture out to cluster outskirts.
Needed data products: Emission line data products (e.g. Ha, [NII] line maps), galaxy classification maps (based on both emission and absorption line measurements), cluster membership information
Publication Date: 01/06/2025