EPIC-XMM-Newton Observations of two nearby Galaxy Clusters

摘要

The XMM-Newton observatory, with its high throughput in combination with the EPIC CCD-cameras, is an ideal instrument to study extended sources like clusters of galaxies. Very deep observations of galaxy clusters reveal substructure on different levels: structure associated with bright galaxies, faint galaxies, or structure consistent with the merger of groups with the main cluster. Another indication of substructure is the deviation of the temperature of the intra-cluster gas from isothermality. We present XMM-Newton mosaic observations of the nearby clusters A3667 and A754. These clusters are good representatives of the different evolution stages that all clusters experience as they grow from mergers of smaller groups. Hence they show merging at different phases, which is also reflected in the different appearance of their temperature maps, pressure maps and entropy maps.