Astrophysics and Observational Cosmology with Galaxy Clusters.

• Grant number: 23/02709-9
• Support Opportunities: Regular Research Grants
• Duration: June 01, 2023 - May 31, 2025
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Extragalactic Astrophysics
• Principal Investigator: Eduardo Serra Cypriano
• Grantee: Eduardo Serra Cypriano
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Galaxy clusters are the object of study of this research project. We plan to do several studies in the context of the optical surveys: CODEX, S-PLUS and J-PAS, projecting for more future surveys such as the LSST.Due to their privileged position at the top of the process of hierarchical formation of the structures of the Universe, clusters occupy an intersection between astrophysics and observational cosmology. On the one hand, these objects retain, in their quantity and distribution, information about the Universe that moves them, including dark energy. On the other hand, due to its almost closed nature, investigating as cosmic laboratories where it is possible to study properties of dark matter and its possibilities even with baryonic matter.In this project, we intend to use clusters to approach the question of the differences in the amplitude of the density fluctuations of matter between the local Universe and the one predicted from the cosmic background radiation, of the distant Universe: the tension S\textsubscript{8}. Data for this comes from the S-PLUS and J-PAS surveys. I forsee in this project a series of steps towards this direction: $i$) the optical detection of clusters, $ii$) the determination of the gravitational shear field by the shape of distant galaxies, and $iii$) the calibration of the mass relation -Optical observable via weak gravitational lensing in cluster stacks.This project also provides for the continuity of ongoing projects. We study the physics of baryons in clusters, and how they are internalized by heating, heating and cooling the intra-cluster plasma. This is done via scaling relationships between mass and magnitudes observed with x-rays and microwaves, using unpublished data from the CODEX survey.We are also interested in the complexities of the cluster formation process. In particular, when larger violent mergers occur in which the intra-cluster medium detachment from galaxies and dark matter can occur. This type of situation provides several clues about how the merger happened and gives access to a study of the interaction between the various components that constitute a cluster of galaxies in a transient situation, highlighting properties that are not visible in undisturbed systems. (AU)