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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. [email protected]. - PowerPoint PPT Presentation
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Evolution of galaxy cluster scaling and structural properties from XMM observations: probing the physics of structure formation.
Doctorant: Sergey ANOKHINDirectrice de thèse: Monique Arnaud
Séminaire étudiants 1ere année, CEA, Saclay, 24 novembre 2004 [email protected]
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)
Self-similar modelHierarchical model of structure formationWe 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
TzAQ )(
Universal profiles
log
/
c)
[NFW 95]
Z=0Z=0.5Z=1
[Bryan & Norman 98]
M h-1(z) T3/2
Calculation of the cluster parameters
BrightnessSx(θ)
Spectroscopy
dE
EdN )(Density of gas
ne(r)Temperature
T(r), <T>
Mass of gasMgas
Mass of Dark Matter
MDM
Mass totalMtot
EntropyS(r)
The thermodynamic history of gas
10-7
10-6
10-5
10-4
10-3
10-2
10-1
100
0.1 1 10
-2
s-1
keV-1
Energy (keV)
8 keV
2 keV
kT = 1 keV
FeSi
S
Fe L
Direction of calculationSelf-similar model relation
LuminosityLx
Dark Matter Collapse
Comparison between observed and theoretical scaling law
LX T2
S = T/ne2/3 T
S (0.1 R200)
[Ponman et al, 03]
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
[Arnaud & Evrard, 99]
Profiles scaled S T0.65
[Pratt & Arnaud, 04]
2.1 keV2.5 keV2.6 keV2.7 keV6.5 keV
ROSAT & ASCA XMM-Newton
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
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
RXJ0337.7-2522z=0.58
RXJ1334.3+5030z=0.62
