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Revising scaling-relations in groups and galaxy clusters

Grant number: 16/08024-4
Support type:Scholarships in Brazil - Scientific Initiation
Effective date (Start): July 01, 2016
Effective date (End): April 30, 2017
Field of knowledge:Physical Sciences and Mathematics - Astronomy - Extragalactic Astrophysics
Principal Investigator:Tatiana Ferraz Laganá
Grantee:Lucas Ferreira Libonati
Home Institution: Centro de Ciências Exatas e Tecnológicas. Universidade Cruzeiro do Sul (UNICSUL). São Paulo , SP, Brazil
Associated research grant:12/00578-0 - Matter distribution in galaxy clusters: a comprehensive picture of baryons in the largest virialized structures in the universe, AP.JP


Well calibrated scaling relations between observable properties and the total mass of galaxy clusters are important for understanding the physical processes that give rise to them. As the measure of individual masses for a large number of systems is observationally very expensive, scaling relations are also a key ingredient for studies aimed at restricting the cosmological parameters using clusters of galaxies. Scaling relations are mathematical expressions that relate pairs of physical quantities of some system. Usually they are described as power laws around the average distribution, where the data spread according to a log-normal distribution. These relationships are positive correlations with the largest systems in average having higher values for the other quantities. For galaxy clusters, the scaling relations results from the physical formation and evolution of these structures. If gravity is the dominant process, the self-similar models provide simple scaling relations between the basic properties of clusters and the total mass. Three correlations are particularly important: the relationship between the X-ray luminosity and temperature (L_x - T_gas $), the total mass and the temperature(M_tot - T_gas) and the X-ray luminosity and the total mass (L_x - M_tot).However, these relationships are valid only under the hydrostatic equilibrium condition. Thus, quantify errors associated when introduced in the sample objects where the hydrostatic equilibrium assumption is not valid, when analyzing systems with high and low mass together, and when analyzing data from different satellites are of utmost importance. In this context, the aim of this study is to analyze the limits of scaling relations and its dispersion when dealing with a large sample of objects in a wide range of redshift and mass. For this, we will use the catalog MCXC (Piffaretti et al. 2011) that presents the compilation and properties 1743 X-ray systems observed in redshift range of 0,01