The Sunyaev-Zel'dovich effect (SZE) is a powerful mass finder and the M -
Y scaling law, based on the self similarity of cluster of galaxies, is the
useful converter when observations of the Compton parameter Y are
available. The presence of inhomogeneities in the IntraCluster gas (ICg),
breaking the assumed spherical symmetry, isothermality and hydrostatic
equilibrium, results in a scatter along the scaling law. The case of col-
lision between two clusters, when gas and dark matter undergo different
displacement, is a clear example of extreme situation of missing this
symmetry. MareNostrum Universe (MNU), one of the biggest smoothed
particle hydrodynamics (SPH) simulations, has been used for selecting a
sample of mergers and relaxed clusters spanning a total mass in the range
of 10^13 < M/M_SUN < 10^15
The objects of the selected datasets were resimulated with higher resolution and adding non-adiabatic physics (cooling and star formation), performing an analysis of baryonic fraction and thermal Sunyaev-Zel'dovich effect in the two classes in the redshift range 0 < z < 1. We found that the morphology of the cluster affects the baryonic fraction and the integrated Y (introducing a dependence from the position of the observer), leading to possible uncertainties in the scaling relations.
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