| Since the first stars ended their lives by exploding as a supernova, the Universe has been continuously enriched with elements heavier than helium. These elements, like carbon, oxygen, silicon and iron, became the main building blocks of planetary systems and even life. Clusters of galaxies, the largest gravitationally bound objects in the Universe, are very suitable laboratories to study chemical enrichment. They generally consist of hundreds of galaxies and hosted billions of supernova explosions in their history. Contrary to individual galaxies, clusters retain all the supernova products because of their deep potential wells that prevent the gas to escape. A large fraction of the heavy elements is contained in the cluster's hot X-ray emitting plasma. The abundances in this Intra-Cluster Medium (ICM) have been studied extensively with the XMM-Newton X-ray observatory. Using the measured abundances we found that it is possible to constrain supernova models, especially those of type Ia supernovae. However, the uncertainties on the abundances in the XMM-Newton sample do not allow us yet to distinguish statistical noise from intrinsic differences between clusters. Therefore, we propose to use a homogeneous and unbiased sample of 63 clusters observed by the Chandra, XMM-Newton, and Suzaku X-ray observatories to extend the original XMM-Newton sample considerably. By enhancing spectral modeling and cross-calibration we will obtain robust abundances for the entire sample. With these numbers we will be able to unravel the chemical enrichment history of the Universe. |
