Testing the universality of the cluster pressure profile on thermal SZ stacks

Activity: Talk or presentationPresentation at conference/workshop/seminar


The electron pressure profile inside galaxy clusters is the most direct probe of the thermodynamical state of the intra-cluster medium (ICM). A universal pressure profile (UPP) model, which factors out the dependencies on mass and redshift, has been proposed by the pioneering works of Nagai et al. (2007) and Arnaud et al. (2010), and later extensively adopted and confirmed by a number of cluster-related studies. All of these works, however, always employed only a handful of high significance-detected clusters, implying a population-level testing of this profile prediction has since been missing.

In this talk I will present the results of an analysis that explicitly tested the UPP model on a population of 23,820 clusters, obtained merging three independent, pre-existing catalogues built on observational data from the surveys KiDS, SDSS and DESI; the sample spanned the mass range 10^14.0 M_sun<M_500<10^15.1 M_sun and the redshift range 0.02<z<0.98. The pressure profile was measured by stacking clusters on maps of the thermal Sunyaev-Zel'dovich effect obtained with both Planck and ACT, and predicted theoretically employing a halo-model framework which explicitly incorporates systematic effects such as the hydrostatic mass bias and possible cluster miscenterings. The large available cluster statistics allowed us to repeat the analysis for independent bins in M_500 and z, thus probing possible residual dependencies of the UPP parameters with mass or redshift.

The results showed that the proposed UPP model is effective in reproducing the measured profile across the full cluster sample, and any residual drifts of the best-fit parameters with mass and/or redshift are below the estimated uncertainties. This is the first time in which the UPP model has been tested on such a large cluster sample, which is both complete and representative.
Period31 Jul 20232 Aug 2023
Held atACAMAR, China