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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.
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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
Properties of galaxy clusters Visible (stars) • 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)
log(r/ rc) [NFW 95] Z=0 Z=0.5 Z=1 Self-similar model Universal profiles 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 (Lx) or total mass (Mtot) or mass of gas (Mgas) or Entropy (S) • T - temperature • A(z) is parameter of evolution • z – redshift • α – slope [Bryan & Norman 98] M h-1(z) T3/2
Spectroscopy Direction of calculation Self-similar model relation Calculation of the cluster parameters Temperature T(r), <T> Brightness Sx(θ) Density of gas ne(r) Luminosity Lx Mass of Dark Matter MDM Mass of gas Mgas Entropy S(r) The thermodynamic history of gas Mass total Mtot Dark Matter Collapse
Comparison between observed and theoretical scaling law XMM-Newton ROSAT & ASCA S (0.1 R200) LX a T2 2.1 keV 2.5 keV 2.6 keV 2.7 keV 6.5 keV S = T/ne2/3a T Profiles scaled S T0.65 [Pratt & Arnaud, 04] [Ponman et al, 03] [Arnaud & Evrard, 99] • LX -T relation steeper than expected • Entropy excess; S a T~0.65 increase with decreasing T (mass) • Self-similar (dispersion 22 % ) above ~ 0.05 r200 with S T0.65r0.94
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)
The first results RXJ1334.3+5030 z=0.62 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
The End • Merci pour votre attention! Sergey.Anokhin@cea.fr