MeerKAT-derived HI kinematics and the Baryonic Tully-Fisher Relation in the X-ray luminous cluster Abell 3408

TL;DR

This study uses MeerKAT HI observations to analyze galaxy kinematics in the Abell 3408 cluster, modeling 16 galaxies and comparing their baryonic Tully-Fisher relation with field galaxies to understand environmental effects.

Contribution

It introduces a semi-automated pipeline for modeling HI morphology and kinematics and applies it to cluster galaxies, extending the baryonic Tully-Fisher relation analysis.

Findings

Successful modeling of 16 cluster galaxies' HI kinematics

The cluster galaxies extend the baryonic Tully-Fisher relation in mass and velocity

The relation's slope is consistent with previous field galaxy studies

Abstract

Significant advances in observational capabilities are continuously transforming our understanding of the dense environment of galaxy clusters and its impact on individual galaxies. Discerning between intrinsic and externally-induced properties of galaxies, including their gas kinematics, is a key diagnostic in the field of galaxy evolution. In this work, we present MeerKAT HI spectral line observations of the redshift z $\sim$ 0.042 galaxy cluster Abell 3408. A total of 64 galaxies are detected in HI in this X-ray-luminous galaxy cluster (L$_{X}$ $\sim$ 3 $\times$ 10$^{43}$ ergs s$^{-1}$). We model the HI morphology and gas kinematics of the individual galaxies, using a semi-automated pipeline based on CANNUBI and pyBBarolo. The pipeline was developed and tested as part of this study. Of the 64 galaxies detected in the cluster, we successfully modelled 16, while the remaining galaxies exhibit disturbed HI morphologies, insufficient angular or velocity resolution. We combine the galaxies with converged kinematic fits with 67 field galaxies from the MeerKAT spectral line survey early science data ($\langle$z$\rangle$ = 0.0435) to produce a measurement of the Baryonic Tully-Fisher Relation (bTFr) that encompasses a broader range of environment and provides a useful comparison. We find a slope ($\alpha$ = 3.66$^{+0.32}_{-0.28}$) for this relation, which is consistent with that found from the MIGHTEE bTFr derived from the same definition. Interestingly, HI detections of the Abell 3408 galaxy cluster galaxies are seen to extend the bTFr of the MIGHTEE sample, both in mass and velocity, despite their cluster environment.