English

CHEX-MATE: Characterization of the intra-cluster medium temperature distribution

Cosmology and Nongalactic Astrophysics 2024-01-31 v1 Astrophysics of Galaxies

Abstract

We study the perturbations in the temperature (and density) distribution for 28 clusters selected from the CHEX-MATE sample to evaluate and characterize the level of inhomogeneities and the related dynamical state of the ICM. We use these spatially resolved 2D distributions to measure the global and radial scatter and identify the regions that deviate the most from the average distribution. During this process, we introduce three dynamical state estimators and produce clean temperature profiles after removing the most deviant regions. We find that the temperature distribution of most of the clusters is skewed towards high temperatures and is well described by a log-normal function. There is no indication that the number of regions deviating more than 1σ\sigma from the azimuthal value is correlated with the dynamical state inferred from morphological estimators. The removal of these regions leads to local temperature variations up to 10-20% and an average increase of \sim5% in the overall cluster temperatures. The measured relative intrinsic scatter within R500R_{500}, σT,int/T\sigma_{T,int}/T, has values of 0.170.05+0.08^{+0.08}_{-0.05}, and is almost independent of the cluster mass and dynamical state. Comparing the scatter of temperature and density profiles to hydrodynamic simulations, we constrain the average Mach number regime of the sample to M3DM_{3D}=0.360.09+0.16^{+0.16}_{-0.09}. We infer the ratio between the energy in turbulence and the thermal energy, and translate this ratio in terms of a predicted hydrostatic mass bias bb, estimating an average value of bb\sim0.11 (covering a range between 0 and 0.37) within R500R_{500}. This study provides detailed temperature fluctuation measurements for 28 CHEX-MATE clusters which can be used to study turbulence, derive the mass bias, and make predictions on the scaling relation properties.

Keywords

Cite

@article{arxiv.2311.02176,
  title  = {CHEX-MATE: Characterization of the intra-cluster medium temperature distribution},
  author = {L. Lovisari and S. Ettori and E. Rasia and M. Gaspari and H. Bourdin and M. G. Campitiello and M. Rossetti and I. Bartalucci and S. De Grandi and F. De Luca and M. De Petris and D. Eckert and W. Forman and F. Gastaldello and S. Ghizzardi and C. Jones and S. Kay and J. Kim and B. J. Maughan and P. Mazzotta and E. Pointecouteau and G. W. Pratt and J. Sayers and M. Sereno and M. Simonte and P. Tozzi},
  journal= {arXiv preprint arXiv:2311.02176},
  year   = {2024}
}

Comments

Accepted for publication in A&A