High-resolution tSZ cartography of clusters of galaxies with NIKA at the IRAM 30-m telescope

TL;DR

This paper discusses high-resolution tSZ observations of galaxy clusters using the NIKA instrument at the IRAM 30-m telescope, aiming to study high-redshift clusters and improve cosmological understanding.

Contribution

It presents the development and application of the NIKA instrument for high-resolution tSZ mapping of galaxy clusters at high redshift.

Findings

Successful high-resolution tSZ observations of galaxy clusters.

Demonstrated NIKA's capability for detailed intra-cluster medium studies.

Prepared groundwork for NIKA2's large sample observations.

Abstract

The thermal Sunyaev-Zeldovich effect (tSZ) is a powerful probe to study clusters of galaxies and is complementary with respect to X-ray, lensing or optical observations. Previous arcmin resolution tSZ observations ({\it e.g.} SPT, ACT and Planck) only enabled detailed studies of the intra-cluster medium morphology for low redshift clusters ($z < 0.2$). Thus, the development of precision cosmology with clusters requires high angular resolution observations to extend the understanding of galaxy cluster towards high redshift. NIKA2 is a wide-field (6.5 arcmin field of view) dual-band camera, operated at $100 \ {\rm mK}$ and containing $\sim 3300$ KID (Kinetic Inductance Detectors), designed to observe the millimeter sky at 150 and 260 GHz, with an angular resolution of 18 and 12 arcsec respectively. The NIKA2 camera has been installed on the IRAM 30-m telescope (Pico Veleta, Spain) in September 2015. The NIKA2 tSZ observation program will allow us to observe a large sample of clusters (50) at redshift ranging between 0.5 and 1. As a pathfinder for NIKA2, several clusters of galaxies have been observed at the IRAM 30-m telescope with the NIKA prototype to cover the various configurations and observation conditions expected for NIKA2.