1. Evolution of clusters M. Arnaud CEA - service d’astrophysique Saclay Assuming favored cosmology  =0.3  =0.7

2. The sample RX J2237 z=0.30 kT =3 ±0.5 keV RX J0256 z=0.36 kT =5 ±0.5 keV RX J1120 z=0.6 kT =5.3 ±0.5 keV Clusters from SHARC survey [Romer et al 00; Nichol et al 99; Burke et al 03] XMM follow up [ Sharc/SSC/SOC/EPIC collaboration] in - GT time (P.I J. Bartlett) [Lumb et al 03] 7 clusters 0.45 < z < 0.62 - OT time (P.I MA) 7(6) clusters 0.3 < z < 0.4 ==> Work in progress from combined set Some Images: [Arnaud et al, A&A, 02][Majerowicz et al, A&A, 03]

3. What do we expect ? Abell 3158 z=0.06 XMM 2.6 M pc RXJ 1120 z=0.6 ROSAT ICM: evolving in the gravitational potential of the DM: f gas = cst ; GM V /R  kT Clusters collapsed at z correspond to a fixed density contrast: GM V /R 3 = <  DM   c (z) ;  Evolution with z via  c (z)  h 2 (z) Scaling laws: Q = A(z)T  : M gas  M V  h -1 (z) T 3/2 R v  h -1 (z) T 1/2 L X  h(z) T 2 For a given mass: at higher z: clusters are denser, smaller, brighter

4. The evolution of the Lx -T relation There is evolution ! A bit larger than expected? in agreement with Chandra [ Vikhlinin et al, 2002] For standard DM model: L x  f 2 gas (T,z) / 2 h(z) T 2 Could indicate evolving: f gas (T) and/or shape ==> Look at gas density (EM) profiles (normalisation and shape)

5. Scaled according to standard evolution: EM sc = h(z) -3 T -1.38 EM NB ‘ non standard ’ but cst EM-T slope Compared to local profile ~ agreement for individual profiles [ taken into account local dispersion and errors] ~ Similar shape BUT systematic discrepancies... Most profiles above local curve [stronger effect for higher z sample] More evolution ? (as for L x -T) S x EM = ∫ n 2 gas dl  h(z) 3 ? Self -similar evolution of the the gas distribution ? Prediction: clusters are denser:  gas   DM   c (z)  h(z) 2 and smaller: R v  h(z) -1 [Arnaud et al, in prep]

6. Temperature profile First (~ precise) measurement of temperature distribution at z=0.6 XMM observation of RXJ 1120 [Arnaud et al A&A, 2002] Flat kT profile up to 0.5 virial radius (as at z~0) RXJ 1120 T =5.3 keV z=0.6

7. CONCLUSIONS XMM results show: Clusters do form a self-similar population down to kT~ 2keV and up to high kT and z Self similarity of form beyond core Scaling laws with z (and kT ) First evidence that numerical simulation predict the correct shape for the DM distribution up to virial radius Self-similarity differs from purely gravitational model Normalisation of the M-T relation ==> (universal) ICM structure not correct Slopes : EM-T : steeper ; S-T shallower: likely due to overall gas content Possible stronger evolution of ICM scaling laws ==> modelling of the DM collapse probably OK ==> Gas physics still to be better understood Current pre-heating models failure What is needed: Larger local samples on wide kT range ==> e.g. M-T relation; c(M) ?; dispersion in ICM scaling laws and origin Larger distant samples ==> e.g. evolution of both normalisation and slopes