Aglomerado de galáxias em estágios evolutivos distintos

Abstract

In recent years, studies have shown that the spatial distribution of temperature and metallicity varies depending on the dynamic state and the evolutionary stage in which clusters are. Based on an analysis of 165 cluster with z <0,35, Jones (2014) showed that 56% of the objects in this sample form multiple systems and have signatures of mergers in progress. The present work aims to analyze the possible relationship between the spatial distribution of parameters such as temperature and metallicity of the intra-cluster medium (ICM) with the evolutionary stage of the system. For this, we selected three clusters observed with the XMM-Newton satellite, in apparently distinct evolutionary stages: PLCKESZ G337.09-25.97 (G337; pré-merger), PLCKESZG036.72 + 14.92 (G036; in merging) and PLCKG292.5 + 22.0 (G292, post-merger). We analyzed the spatial distribution of temperature and metallicity from the spectral fits in different regions. We construct temperature and metallicity profiles along the line of shock and also construct two-dimensional maps of these parameters to analyze their global variation. Our results show a temperature rise in the region between the two X-ray emission peaks for the G292 cluster (which has already undergone the merging process), a temperature twice the temperature found for the cluster G337, which presents two isolated systems. In addition ,the Mach number for the G292 is 1,47 (super-sonic) while for the G036 it is 1,25, in agreement with results from the literature. Comparing the results obtained from the X-ray analysis with results from numerical simulations performed by a collaborator of the group, we were able to characterize in detail the process of merger for two systems: G036 and G292. The angle of inclination between the plane of the orbit and the plane of the sky for G036 is 50 . Comparing the results obtained in the 2D maps with the temporal evolution of the merger, this system is at t = 60 Myr before the pericentric passage. The time t, is the time that corresponds to the time that best reproduces the observed characteristics in x-ray. As for the G292 system, the simulations revealed that this system, initially classified as post-merger, was a merger system. Comparing the results of the hydrodynamic simulations with those obtained in X-ray, this system is at 150 Myr before the pericentric passage. This merger occurs almost in the plane of the sky (they have an inclination angle of 18 ). With this work, we conclude that the joint analysis of X-ray data and numerical simulations can characterize in detail the dynamics of merging clusters.