MeerKAT-derived H i kinematics and the baryonic Tully–Fisher relation in the X-ray luminous cluster Abell 3408

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 the intrinsic and the externally induced properties of galaxies, including their gas kinematics, is a key diagnostic in the field of galaxy evolution. In this paper, we present MeerKAT H i spectral line observations of the redshift z ~ 0.042 galaxy cluster Abell 3408. A total of 64 galaxies are detected in H i in this X-ray luminous galaxy cluster (LX ~ 3 × 1043 erg s⁻¹). We model the H i morphology and gas kinematics of the individual galaxies, using a semi-automated pipeline based on cannubi and py bbarolo. 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 H i 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 (z = 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 (α = 3.66+0.32-0.28) for this relation, which is consistent with that found from the MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) survey bTFr derived from the same definition. Interestingly, H i 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.