First Sunyaev–Zel’dovich mapping with the NIKA2 camera: Implication of cluster substructures for the pressure profile and mass estimate
Résumé
The complete characterization of the pressure profile of high-redshift galaxy clusters, from their core to their outskirts, is a major issue for the study of the formation of large-scale structures. It is essential to constrain a potential redshift evolution of both the slope and scatter of the mass-observable scaling relations used in cosmology studies based on cluster statistics. In this paper, we present the first thermal Sunyaev–Zel’dovich (tSZ) mapping of a cluster from the sample of the New IRAM Kids Arrays (NIKA2) SZ large program that aims at constraining the redshift evolution of cluster pressure profiles and the tSZ-mass scaling relation. We observed the galaxy cluster PSZ2 G144.83+25.11 at redshift z = 0.58 with the NIKA2 camera, a dual-band (150 and 260 GHz) instrument operated at the Institut de Radioastronomie Millimtrique (IRAM) 30-m telescope. We identify a thermal pressure excess in the south-west region of PSZ2 G144.83+25.11 and a high-redshift sub-millimeter point source that affect the intracluster medium (ICM) morphology of the cluster. The NIKA2 data are used jointly with tSZ data acquired by the Multiplexed SQUID/TES Array at Ninety Gigahertz (MUSTANG), Bolocam, and Planck experiments in order to non-parametrically set the best constraints on the electronic pressure distribution from the cluster core (R ~ 0.02R500) to its outskirts (R ~ 3R500). We investigate the impact of the over-pressure region on the shape of the pressure profile and on the constraints on the integrated Compton parameter Y500. A hydrostatic mass analysis is also performed by combining the tSZ-constrained pressure profile with the deprojected electronic density profile from XMM-Newton. This allows us to conclude that the estimates of Y500 and M500 obtained from the analysis with and without masking the disturbed ICM region differ by 65% and 79%, respectively. This work highlights that NIKA2 will have a crucial impact on the characterization of the scatter of the Y500−M500 scaling relation due to its high potential to constrain the thermodynamic and morphological properties of the ICM when used in synergy with X-ray observations of similar angular resolution. This study also presents the typical products that will be delivered to the community for all clusters included in the NIKA2 tSZ Large Program.Key words: galaxies: clusters: intracluster medium / cosmology: observations / instrumentation: high angular resolution
| Origine | Publication financée par une institution |
|---|