In this paper, we report the relative supernovae (SNe) contribution to the metal budget of the intracluster medium (ICM) of the Abell 1837 galaxy cluster at redshift z = 0.069. For this purpose, we analysed the hot ICM of the cluster and obtained radial metal distributions using XMM–Newton archival data with a total exposure of ∼100 ks. These metal measurements consist of Mg, Si, S, Fe and Ni within a radius of 0.7 R500, which is divided into three concentric annuli. In order to explain the observed metal abundance pattern in terms of relative supernova contributions, we used our newly developed code SNeRatio, which utilizes theoretical nucleosynthesis models. This study covers the most recent 3D Type Ia SN and core-collapse SN yield tables. All combinations of these theoretical yields were fitted with our measured abundance ratios, and statistically acceptable ones were selected. Each of these models was found to predict a uniform SNIa percentage contribution to the total SNe from the cluster centre to the outskirts and to form an SNIa ratio distribution with a mean of 39 ± 14${{\ \rm per\ cent}}$. This uniformity is consistent with the early enrichment scenario, which assumes that metal production processes begin in the early phase of cluster formation, namely the proto-cluster phase at epoch z ≥ 2.

We present the evidence for the existence of sub-structure in the cold front cluster A2554 based on a 20.14 ks Chandra observation. Using centroid shift and X-ray brightness concentration parameters, we confirm that A2554 is a dynamically disturbed system. We detect two dominant structures: a main cluster at z = 0.1108 and a foreground northern sub-structure at z = 0.1082. The analysis reveals an X-ray surface brightness edge at r ≃ 60 h−1 kpc from the cluster core. The thermodynamical profiles across the edge are ruling out the shock scenario. The temperature jump (from ∼6 keV to ∼10 keV), and pressure equilibrium (P0/P1 = 1.01 ± 0.23) across the edge, are consistent with the definition of a cold front with a Mach number $\mathcal {M}_1=0.94^{+0.13}_{-0.17}$. We also observed a weak bow-shock at ∼100 kpc in front of the cold cloud, corresponding an upper limit to the Mach number $\mathcal {M}_1$ ∼1.1. If the northern sub-structure was not related to the cold front, we conclude that the transonic motion of the cloud is caused by a merger, which was weak or occurred long ago.