SYMPHANY- SYnergy of Molecular PHase And Neutral hYdrogen in galaxies in A2626

Environmental processes in galaxy clusters play a key role in shaping the gas content and star formation activity of galaxies. While atomic gas is known to be highly susceptible to environmental effects, the response of molecular gas to dense environments remains less well understood. We investigate the molecular and atomic gas properties of galaxies in the A2626 cluster (z = 0.055) in order to understand how environmental processes affect different gas phases. We present an analysis of ten spatially resolved galaxies in A2626 observed as part of the SYMPHANY project. Using CO(2–1) observations from ALMA and SMA together with data from MeerKAT, we examine the interplay between molecular and atomic gas through a joint morphological and kinematic analysis. While the kinematic behaviour of and CO is often similar, the atomic gas is morphologically more extended than the centrally concentrated CO distribution, making it more susceptible to environmental stripping. Nevertheless, we also find evidence for molecular gas asymmetries, disturbed velocity fields, and H_2 deficiencies in some galaxies, indicating that molecular gas reservoirs can also be affected in dense environments. Compared to Virgo, a dynamically unrelaxed, non–cool-core cluster, the relaxed cool-core structure of A2626 likely results in less intense ram-pressure stripping. This may allow galaxies to retain more atomic gas, while local interactions or pre-processing may still influence the molecular phase, producing relatively low deficiencies but higher H_2 deficiencies in A2626 galaxies. This behaviour is also reflected in the higher gas fractions, slightly elevated star formation rates, and shorter depletion timescales (0.3–3 Gyr), implying moderately enhanced star formation efficiency. The absence of a clear correlation between H_2 deficiency and cluster-centric distance or velocity suggests that molecular gas evolution in A2626 may be driven more by early infall or local interactions than by the current location of galaxies within the cluster.