1. Structural and scaling properties of galaxy clusters Probing the physics of structure formation M.Arnaud, G.Pratt, E.Pointecouteau (CEA-Sap Saclay) Dark matter distribution in clusters with XMM E.Pointecouteau Some insights into cluster gas physics with XMM G.Pratt Cluster evolution M.Arnaud

2. Physical parameters L bol ~10 41 - a few 10 46 ergs/s M tot ~10 13 - a few 10 15 M o T ~ 0.3 - 15 keV Present at least since z ~ 1.5 Morphology : regular (~50%) but some not  ≠ dynamical state at all z The cluster population: A large variety of objects XMM A1795 z=0.06 Coma z =0.02 XMM RXJ1053 z =1.26 Chandra RXJ0848 z=1.27

3. A 2657 T=3.7 keVA2319 T= 9.1 keV [Mohr & Evrard 1997] RIRI kTkT [Neumann & Arnaud 1999] S x profile But all possible clusters do NOT exist  Correlations  Some regularity in shape

4. (anal. spherical collapse; num simul) ICM: evolving in the gravitational potential of the DM: f gas = cst Clusters collapsed at z correspond to a fixed density contrast: GM/R 3 = <   c (z) ;  Are close to virial/hydrostatic equilibrium (between big mergers) kT  GM/R Have same internal DM (and thus gas) structure Self Similarity of the cluster population expected Universal profiles  Simple scaling laws: Q  T  M  T 3/2 R v  T 1/2 L X  T 2 Z=0 Z=0.5 Z=1 log  /  c ) Comparison with observations  test of formation physics [NFW 1995] [Bryan & Norman 1998] Canonical model of cluster formation

5. From XMM observations to DM profiles 1 – Imaging  surface brightness profile  density profile 2 - Spectroscopy  temperature profile Chandra match XMM! Spherical symmetry + Hydrostatic Equilibrium  Total mass profile

6. Mass profile derived from the HE equation  Cusped profile as expected from num. Simu. (NFW profile preferred)  Similarity observed in the shape of M(r) - deprojection - PSF correction A1413 [Pratt & Arnaud 02] z=0.143 ; kT X =6.49 keV A1983 [Pratt & Arnaud 03] z=0.044 ; kT X =2.3 keV A478 [Pointecouteau et al. 03] z=0.088 ; kT X =6.73 keV - down to 0.01 virial radius - up to 0.7 virial radius

7. Chandra on 5 relaxed hot/lensing clusters : M  T 1.52±0. 36 The M-T relation from XMM/chandra Modelling of DM collapse OK; Pb in gas modelling (distribution shape)  = 2500 (0.3 r 200 ) XMM on 3 relaxed cooling flow clusters : M  T 1.49±0.2  Normalisation offset at  = 2500 (0.3 r 200 )… and at all radii (  ) At a given R corresponding to a density constrast  : M  =   T 3/2   depends on the (universal) gas and DM distribution, via HE

8. Conclusion XMM-Newton  Unpreecedent accuracy on kT(r)  First detailed DM profiles for clusters (up to R v ) Similarity in the dark matter shape of cluster  Dark matter collapse seems to be well understood  Better constraints needed to characterize the central region:  NFW preferred  ideal world: XMM+Chandra Departure from predicted M-T relation normalisation  Modelling of the gas still not reproducing real clusters  Physics of the gas not well understood (G.Pratt)  Evolution of scaling properties with z (M.Arnaud)