http://arxiv.org/abs/1607.00019
We analyze hydrodynamical and cosmological simulations of galaxy clusters to study scaling relations between the cluster total masses and observable quantities such as gas luminosity, gas mass, temperature, and YX , i.e., the product of the last two properties. Our simulations are performed with the Smoothed-Particle-Hydrodynamic GADGET-3 code and include different physical processes. The twofold aim of our study is to compare our simulated scaling relations with observations at low (z~0) and intermediate (z~0.5) redshifts and to explore their evolution over the redshift range z=0-2. The result of the comparative study shows a good agreement between our numerical models and real data. We find that AGN feedback significantly affects low-mass haloes at the highest redshifts resulting in a reduction of the slope of the mass-gas mass relation (~13%) and the mass-YX relation (~10%) at z=2 in comparison to z=0. The drop of the slope of the mass-temperature relation at z=2 (~14%) is, instead, caused by early mergers. We investigate the impact of the slope variation on the study of the evolution of the normalization. We conclude that the observed scaling relations should be limited to the redshift range z=0-1 for cosmological studies because in that redshift range the slope, the scatter, and the covariance matrix of the relations do not exhibit significant evolution. The mass-YX relation continues to be the most suitable relation for this goal. Extending the analysis to the redshift range between 1 and 2 will be crucial to evaluate the impact generated by the AGN feedback.
N. Truong, E. Rasia, P. Mazzotta, et. al.
Mon, 4 Jul 16
2/58
Comments: 15 pages, 9 figures, 4 tables. Comments are welcome
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