1. The morphology of clusters of galaxies: the cluster-galaxy connection Irini Sakelliou Birmingham : T. Ponman MPIA : S. Falter, V. Smolcic, E. Bell MPE : A. Finoguenov Colorado: P. Motl

2. Ringberg 2005 How structure is formed The formation of a Coma- like cluster. Left panels : Dark matter Right panels : Hot gas

3. Ringberg 2005 Galaxy-Cluster interactions They should affect both : the cluster and its galaxies An infalling galaxy in A2125 (z~0.25) Chandra/HST/VLA/KPNO images 01-06-04 NASA press release

4. Ringberg 2005 Temperature maps Contours= surface brightness How/when and at which stage of cluster formation a) the galaxies are affected/tranformed and b) the ICM is affected by the infalling material?

5. Ringberg 2005 Simple measures of the structure. That it can work with X-ray and optical and simulated images Centroid offset : Determination of the centre of the distribution in annuli of increasing radius. The annuli are not concentric. Ellipticity Position Angle

6. Ringberg 2005 Ellipticity & Position angle Accumulation of counts (cnt) along circular annuli (  ). If the 2D distribution is elliptical the cnt-  plot should have 2 peaks. The shape of the cnt-  plot depends on the ellipticity and the position angle.

7. Ringberg 2005 Abell 2255 XMM-Newton image in the (0.3 - 10.0) keV energy range (~14ks MOS exposure) Abell 2255 is a ~7keV at z=0.08 SDSS cluster galaxies. Red circle = XMM FOV

8. Ringberg 2005 High-z cluster at z=0.22 from COSMOS (Smolcic et al. 2006) It is a poor cluster, in the process of merging with other groups. X-ray contours Red cluster galaxies Blue galaxies

9. Ringberg 2005 A2255: Centroid offset X-rays: ICM distributionOptical : galaxy distribution

10. Ringberg 2005 Ellipticity & Position angle

11. Ringberg 2005 A2255: position angle

12. Ringberg 2005 Summary, Concluding remarks, & future A simple method to determine the dynamical ‘age’ of clusters from X-ray and optical observations There are still problems to be solved (e.g., errors) We need simple methods for determining the structure of clusters if we want to go higher redshifts Use simulated X-ray images to set the baseline z= 0.25 Simulated X-ray images from Motl et al.2004 z= 0.00