Clusters of galaxies in X-rays: Distribution of baryonic and non-baryonic matter.

Clusters of galaxies consist of various components: galaxies, dark matter, intra-cluster gas, magnetic fields etc. Interaction of the different component yields important information on physical quantities like e.g. the pressure, the energy or the strength of the magnetic field. The knowledge about these quantities enables us to understand cluster formation as well as physical processes in clusters - both important steps to use clusters as diagnostic tools for cosmology. We present the analysis of baryonic and non-baryonic matter distribution in a sample of ten nearby clusters (0.09>z>0.03) with temperatures between 4.7 and 9.4 keV. These galaxy clusters are studied in detail using X-ray data and global physical properties are determined. Correlations between these quantities are analysed and compared with the results for distant clusters. We find an interesting correlation between the extent of the intra-cluster gas relative to the dark matter distribution. The extent of the gas relative to the extent of the dark matter tends to be larger in less massive clusters. This correlation might give us some hints on non-gravitational processes in clusters. The higher sensitivity and spatial resolution of the new X-ray satellites XMM and Chandra allow us to study clusters in more detail. As an example we present the discovery of depressions in the X-ray emission of the distant galaxy cluster RBS797 in a Chandra observation, and the XMM observation of the dynamically young galaxy cluster CL 0939+4713.

 

Fecha: 
21/01/2004 - 13:00
Conferenciante: 
África Castillo Morales
Filiación: 
Universidad de Granada


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