1. Evolution of galaxy cluster scaling and structural properties from XMM observations: probing the physics of structure formation. Doctorant: Sergey ANOKHIN Directrice de thèse: Monique Arnaud Séminaire étudiants 1ere année, CEA, Saclay, 24 novembre 2004 Sergey.Anokhin@cea.fr

2. Properties of galaxy clusters Visible view of clusters:  A group of bound galaxies (galaxies ~2% of the total mass) X-ray view of clusters:  The spherical cloud of gas with increasing density to the center (gas ~13% of the total mass) Lensing and X-ray view of cluster:  Dark Matter (~85% of the total mass) X-ray (gas) Visible (stars)

3. Self-similar model Hierarchical model of structure formation We assumed that the formation and the evolution of structures is simple and driven by the collisionless gravitational collapse of the main dark matter (DM) component  the population of galaxy clusters is self similar  Q is: Luminosity (L x ) or total mass (M tot ) or mass of gas (M gas ) or Entropy (S) T - temperature A(z) is parameter of evolution z – redshift α – slope Universal profiles log  /  c ) [NFW 95] Z=0 Z=0.5 Z=1 [Bryan & Norman 98] M  h -1 (z) T 3/2

4. Calculation of the cluster parameters Brightness S x (θ) Spectroscopy Density of gas n e (r) Temperature T(r), Mass of gas M gas Mass of Dark Matter M DM Mass total M tot Entropy S(r) The thermodynamic history of gas Direction of calculation Self-similar model relation Luminosity L x Dark Matter Collapse

5. Comparison between observed and theoretical scaling law L X  T 2 S = T/n e 2/3  T S (0.1 R 200 ) [Ponman et al, 03]  L X -T relation steeper than expected  Entropy excess; S a T ~0.65 increase with decreasing T (mass)  Self-similar (dispersion  22 % ) above ~ 0.05 r 200 with S  T 0.65 r  0.94 [Arnaud & Evrard, 99] Profiles scaled S  T 0.65 [Pratt & Arnaud, 04] 2.1 keV 2.5 keV 2.6 keV 2.7 keV 6.5 keV ROSAT & ASCA XMM-Newton

6. Non-gravitational processes in clusters: heating and cooling The gas scaling properties are different from expected in the simple gravitational model Cluster gas is not purely governed by gravitational effects Starting point of this research: The recent ideas to explain these deviations based on processes of:  (pre)heating (SuperNova, Active Galaxy Nucleus…);  cooling (conductivity…); Cooling and heating processes in clusters are not yet well understood. To study these phenomenon it is necessary to understand the history of clusters: compare distant clusters at large redshifts and nearby clusters (~20 clusters from opentime and archives)

7. The first results Two galaxy clusters with the software package « XMM-Newton Science Analysis System » are processed Access to database of “XMM-Newton Science Archive” Filtering  Event list cleaning  Background event list  Point sources cleaning Creation of the images and visual verification of the data processing RXJ0337.7-2522 z=0.58 RXJ1334.3+5030 z=0.62

8. The End Merci pour votre attention! Sergey.Anokhin@cea.fr