Galaxy clusters as probes for cosmology and dark matter

TL;DR

Galaxy clusters, observed via the Sunyaev--Zel'dovich effect, are increasingly vital for cosmological research, offering insights into structure formation, reionization, and dark matter, with future measurements promising even more detailed understanding.

Contribution

This paper reviews recent progress in galaxy cluster observations using SZ effect surveys and discusses future prospects for cosmological and dark matter studies.

Findings

Large galaxy cluster samples have been built from wide-area surveys.

Optical/NIR and X-ray follow-ups are enhancing cluster characterization.

Future SZ measurements will enable detailed high-redshift universe studies.

Abstract

In recent years, significant progress has been made in building new galaxy clusters samples, at low and high redshifts, from wide-area surveys, particularly exploiting the Sunyaev--Zel'dovich (SZ) effect. A large effort is underway to identify and characterize these new systems with optical/NIR and X-ray facilities, thus opening new avenues to constraint cosmological models using structure growth and geometrical tests. A census of galaxy clusters sets constraints on reionization mechanisms and epochs, which need to be reconciled with recent limits on the reionization optical depth from cosmic microwave background (CMB) experiments. Future advances in SZ effect measurements will include the possibility to (unambiguously) measure directly the kinematic SZ effect, to build an even larger catalogue of galaxy clusters able to study the high redshift universe, and to make (spatially-)resolved galaxy cluster maps with even spectral capability to (spectrally-)resolve the relativistic corrections of the SZ effect.