The XXL Survey. LI. Pressure profile and YSZ − M scaling relation in three low-mass galaxy clusters at z ∼ 1 observed with NIKA2
Abstract
Context. The thermodynamical properties of the intracluster medium (ICM) are driven by scale-free gravitational collapse, but they also reflect the rich astrophysical processes at play in galaxy clusters. At low masses (∼1014 M⊙) and high redshift (z ≳ 1), these properties remain poorly constrained, observationally speaking, due to the difficulty in obtaining resolved and sensitive data.
Aims: We aim to investigate the inner structure of the ICM as seen through the Sunyaev-Zel'dovich (SZ) effect in this regime of mass and redshift. We focused on the thermal pressure profile and the scaling relation between SZ flux and mass, namely the YSZ − M scaling relation.
Methods: The three galaxy clusters XLSSC 072 (z = 1.002), XLSSC 100 (z = 0.915), and XLSSC 102 (z = 0.969), with M500 ∼ 2 × 1014 M⊙, were selected from the XXL X-ray survey and observed with the NIKA2 millimeter camera to image their SZ signal. XMM-Newton X-ray data were used as a complement to the NIKA2 data to derive masses based on the YX − M relation and the hydrostatic equilibrium.
Results: The SZ images of the three clusters, along with the X-ray and optical data, indicate dynamical activity related to merging events. The pressure profile is consistent with that expected for morphologically disturbed systems, with a relatively flat core and a shallow outer slope. Despite significant disturbances in the ICM, the three high-redshift low-mass clusters follow the YSZ − M relation expected from standard evolution remarkably well.
Conclusions: These results indicate that the dominant physics that drives cluster evolution is already in place by z ∼ 1, at least for systems with masses above M500 ∼ 1014 M⊙.
- Publication:
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Astronomy and Astrophysics
- Pub Date:
- April 2024
- DOI:
- 10.1051/0004-6361/202348049
- arXiv:
- arXiv:2310.05819
- Bibcode:
- 2024A&A...684A..18A
- Keywords:
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- techniques: high angular resolution;
- galaxies: clusters: intracluster medium;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 24 pages, published in A&