{"id":3225,"date":"2025-12-15T11:41:47","date_gmt":"2025-12-15T10:41:47","guid":{"rendered":"https:\/\/lpsc-wordpress.in2p3.fr\/?page_id=3225"},"modified":"2026-07-03T16:18:12","modified_gmt":"2026-07-03T14:18:12","slug":"lpsz-webpage","status":"publish","type":"page","link":"https:\/\/lpsc-wordpress.in2p3.fr\/?page_id=3225","title":{"rendered":"LPSZ webpage"},"content":{"rendered":"\n

\n\t\t\tThe NIKA2 SZ Large Program\t<\/h2>\n
\n\t\t\t\t\"Logo_NIKA2\"\n\t<\/figure>\nCosmology and cluster physics with a sample of SZ-selected clusters\n\t\t\t\tScientific context\n\t\t\t\tTeam\n\t\t\t\tPublications\n\t\t\t\tData Release\n\t\t\t\tPhD thesis\n\t\t\t\tA pilot study with NIKA\n\t\t\t\t\t\t\tScientific context\n\t\t\t\t

The NIKA2 SZ Large Program was conceived to exploit the unique capabilities of the NIKA2 camera to obtain high-resolution tSZ observations of a representative sample of galaxy clusters at intermediate and high redshifts (0.5 < z < 0.9).\u00a0<\/p>\n

The LPSZ offers the first SZ-selected sample in this regime with sufficient angular resolution to study the ICM in great detail and thereby to enhance our understanding of galaxy clusters. More precisely, we aimed at understanding the physical processes driving the evolution of massive halos in the Universe and quantify how their thermal content and spatial distribution evolve as they grow through accretion and mergers. In turn, the goal was to obtain a more precise characterization of the SZ-mass scaling relation and its possible redshift dependence within a regime critical for high-precision, cluster-based cosmological analyses<\/p>\n

The scientific drivers have been built upon a synergy between SZ data from NIKA2 and X-ray data from XMM-Newton satellite, which share the same high-resolution characteristics. Indeed, the combination of tSZ and X-ray data provides a powerful means of probing the intracluster medium (ICM) thermodynamics and of quantifying how its thermal content and spatial distribution evolve as clusters grow through accretion and mergers.<\/p>\n

The LPSZ data have first been used to study individual clusters, which have demonstrated the full scientific potential of the SZ Large Program.<\/p>\n

In\u00a0Ruppin et al. 2018<\/a>, we presented the first SZ mapping of a galaxy cluster belonging to the NIKA2 SZ Large Program sample. We showed that PSZ2 G144.83+25.11 exhibits an overpressure region that affects both the pressure profile and the constraints on the integrated Compton parameter. In\u00a0K\u00e9ruzor\u00e9 et al. 2020<\/a>, we published the data for the most challenging cluster in the sample, characterized by low mass, high redshift, and strong contamination from point sources. In Mu\u00f1oz Echeverr\u00eda et al. 2023<\/a>, we investigated the impact of systematic effects on mass reconstruction in the case of the galaxy cluster CL J1227. The comparison with lensing data allowed us to estimate the hydrostatic bias. In Paliwal et al. 2025<\/a>\u00a0we classified ACT-CL J0240.0+0116 as disturbed, using morphological indicators derived from its SZ, X-ray, and optical image.\u00a0 In\u00a0Ferragamo et al. 2022<\/a>,\u00a0we have presented a comparison between the hydrostatic and lensing mass profiles of the cluster MACS J0647.7+7015 and found significant variation in the cluster mass estimate depending on the observable, the modeling of the data, and the knowledge of the cluster’s dynamical state.\u00a0<\/p>\n

The final goal of the LPSZ is the study of the full sample that is described in a series of papers (NIKA2 LPSZ results). It includes description of 150 and 260 GHz maps, the\u00a0 characterization\u00a0 of\u00a0 point-source\u00a0 populations\u00a0 in clusters,\u00a0 the\u00a0 measurement\u00a0 of\u00a0 thermodynamic profiles\u00a0 and\u00a0 integrated\u00a0 ICM\u00a0 quantities,\u00a0 the determination of the universal pressure profile, constraints\u00a0 on\u00a0 the\u00a0 SZ-mass\u00a0 scaling\u00a0 relation, an analysis of SZ fluctuations associated with non-thermal processes and a morphological classification of clusters of galaxies.<\/p>\n\t\t\t\t\t\t\tTeam\n

The LPSZ team<\/h2>\n
\n

Principal Investigators : <\/b>F. Mayet<\/a>\u00a0 and L. Perott<\/a>o (LPSC Grenoble)<\/p>\n