X-ray study of the intracluster medium of Abell 4038 with XMM-Newton

Abstract

The intracluster medium offers a detailed way of studying the metal enrichment in the Universe. An X-ray observation of Abell 4038, a rich cluster of galaxies, is made with XMM-Newton with an exposure time of 67 ks. After filtering the data from soft-proton flaring, the spectrum of the core region with radius 0.2 R500 is extracted. By fitting the background components and the cluster emission, the temperature and abundances of O, Ne, Mg, Si, S, Ar, Ca, Fe and Ni are obtained. With the abundances the ratio between type Ia and core-collapse supernovae is calculated and compared with other papers (e.g. de Plaa et al. 2007, Sato et al. 2007). The spectra of 7 concentric annuli are also extracted, resulting in the radial profiles for the temperature and the abundances of iron and silicium. The temperature profile indicates that A4038 is a cool-core cluster, and the centrally peaked abundances suggest that the cluster is in a relaxed state. Furthermore, a Beta-model is fitted through the radial profile of the surface brightness to obtain the core radius 'rc'. The small value of this radius is similar to that of other relaxed clusters, indicating again that A4038 is a relaxed cluster.