Brief history of the metal accumulation in the intracluster medium

Abstract

We use models of the rates of Type Ia supernovae (SNe Ia) and core-collapse supernovae, built in such a way that both are consistent with recent observational constraints at z<1.6 and can reproduce the measured cosmic star formation rate, to recover the history of the metals accumulation in the intra-cluster medium. We show that these SN rates, in unit of SN number per comoving volume and rest-frame year, provide on average a total amount of Iron that is marginally consistent with the value measured in galaxy clusters in the redshift range 0-1, and a relative evolution with redshift that is in agreement with the observational constraints up to z~1.2. Moreover, we verify that the predicted metals to Iron ratios reproduce the measurements obtained in nearby clusters through X-ray analysis, implying that (1) about half of the Iron mass and >75 per cent of the Nickel mass observed locally are produced by SN Ia ejecta, (2) the SN Ia contribution to the metal budget decreases steeply with redshift and by z~1 is already less than half of the local amount and (3) a transition in the abundance ratios relative to the Iron is present between redshifts ~0.5 and 1.4, with core-collapse SN products becoming dominant at higher redshifts.

8 pages, MNRAS in press. Minor changes to match published version