Speaker
Description
Current cosmological studies based on clusters of galaxies are limited by the accuracy with which the mass of these objects can be inferred. The Sunyaev-Zel'dovich (SZ) effect is a direct probe of the thermal pressure of the Intra-Cluster Medium (ICM). When combined with X-ray data, the SZ effect can also provide a valuable measure of the mass of the galaxy clusters under the hydrostatic equilibrium assumption. With an angular resolution comparable to that of the XMM-Newton space observatory, NIKA2 will unveil the pressure distribution of the ICM and will allow the full deployment of combined SZ and X-ray methods to infer the hydrostatic mass.
The Guaranteed-Time SZ Large Program (LP-SZ) is dedicated to the high-angular resolution SZ mapping of a representative sample of 45 galaxy clusters drawn from the SZ-selected catalogues of the Planck satellite, or of the Atacama Cosmology Telescope. The LP-SZ sample spans a mass range from 3 to 11x10^{14} M_{sun} and a redshift range from 0.5 to 0.9, extending to higher redshift and lower mass the previous samples dedicated to the cluster mass calibration and universal properties estimation. The main goals of the LP-SZ are the measurement of the average radial profile of the ICM pressure up to R_500 by combining NIKA2 with Planck or ACT data, and the estimation of the scaling law between the SZ observable and the mass using NIKA2, XMM-Newton and Planck/ACT data. Furthermore, combining LP-SZ data with existing or forthcoming public data in lensing, optical/NIR or radio domains, we will build a consistent picture of the cluster physics and further gain knowledge on the mass estimate as a function of the cluster morphology and dynamical state. In this talk, I will present the LP-SZ, the recent results obtained within this framework, the status of the observation and analysis, and the future implication for cosmology with galaxy clusters.
