Orateur
Description
Galaxy cluster are the most massive gravitationally bound structures in the Universe, thus, they are of great cosmological interest. Indeed, their mass and redshift distribution can be used to constrain cosmological parameters.
In order to study clusters we can use the thermal Sunyaev-Zel'dovich (tSZ) effect that is produced by the inverse Compton interaction of CMB photons with the hot gas of the clusters and which is not affected by cosmological dimming.
The tSZ effect is directly proportional to the electron pressure integrated along the line-of-sight and along with X-ray data it allows us to study cluster thermodynamic properties. Moreover, under the hypothesis of hydrostatic equilibrium it's then possible to obtain a lower biased estimate of the total mass of the cluster and establish scaling relations.
Physical processes in individual clusters as merging events, shocks and turbulence can modify this hydrostatic bias and then limit the cosmological exploitation of the cluster sample. At this regard high resolution tSZ observations are particularly useful as they allow to characterize cluster spatial properties and morphology.
In this talk we will present 18 arcsec resolution NIKA2 tSZ observations at 150 GHz of a CHEXMATE cluster of galaxies presenting a disturbed morphology. Combining with X-ray data we will derive the main cluster thermodynamic quantities in terms of radial profiles and associate 2D residuals to physical cluster properties. We will also discuss how higher resolution tSZ observations with the NOEMA IRAM interferometer are of interest to probe the cluster inner regions down to BCG scales.