Cluster cosmology with the NIKA2 SZ Large Program

TL;DR

This paper presents the NIKA2 SZ large program, which uses high-resolution SZ observations to study galaxy clusters at high redshift, aiming to improve mass estimates and understand potential biases in cosmological analyses.

Contribution

It introduces the NIKA2 SZ large program and demonstrates its capability to observe and characterize high-redshift galaxy clusters with high angular resolution.

Findings

First cluster observed with NIKA2 characterized.

Potential to reduce systematic uncertainties in cluster mass estimates.

Enhanced understanding of pressure profiles at high redshift.

Abstract

The main limiting factor of cosmological analyses based on thermal Sunyaev-Zel'dovich (SZ) cluster statistics comes from the bias and systematic uncertainties that affect the estimates of the mass of galaxy clusters. High-angular resolution SZ observations at high redshift are needed to study a potential redshift or morphology dependence of both the mean pressure profile and of the mass-observable scaling relation used in SZ cosmological analyses. The NIKA2 camera is a new generation continuum instrument installed at the IRAM 30-m telescope. With a large field of view, a high angular resolution and a high-sensitivity, the NIKA2 camera has unique SZ mapping capabilities. In this paper, we present the NIKA2 SZ large program, aiming at observing a large sample of clusters at redshifts between 0.5 and 0.9, and the characterization of the first cluster oberved with NIKA2.