Clustering of CODEX clusters

Abstract

Aims. We analyze the autocorrelation function of a large contiguous sample of galaxy clusters, the Constrain Dark Energy with X-ray (CODEX) sample, in which we take particular care of cluster definition. These clusters were X-ray selected using the RASS survey and then identified as galaxy clusters using the code redMaPPer run on the photometry of the SDSS. We develop methods for precisely accounting for the sample selection effects on the clustering and demonstrate their robustness using numerical simulations. Methods. Using the clean CODEX sample, which was obtained by applying a redshift-dependent richness selection, we computed the two-point autocorrelation function of galaxy clusters in the $0.1<z<0.3$ and $0.3<z<0.5$ redshift bins. We compared the bias in the measured correlation function with values obtained in numerical simulations using a similar cluster mass range. Results. By fitting a power law, we measured a correlation length $r_0=18.7\pm 1.1$ and slope $\gamma =1.98\pm 0.14$ for the correlation function in the full redshift range. By fixing the other cosmological parameters to their WMAP9 values, we reproduced the observed shape of the correlation function under the following cosmological conditions: ${\Omega }_{m_0}=0.22_{-0.03}^{+0.04}$ and $S_8={\sigma }_8({\Omega }_{m_0}/0.3{)}^{0.5}=0.85_{-0.08}^{+0.10}$ with estimated additional systematic errors of ${\sigma }_{{\Omega }_{m_0}}=0.02$ and ${\sigma }_{S_8}=0.20$. We illustrate the complementarity of clustering constraints by combining them with CODEX cosmological constraints based on the X-ray luminosity function, deriving ${\Omega }_{m_0}=0.25\pm 0.01$ and ${\sigma }_8=0.81_{-0.02}^{+0.01}$ with an estimated additional systematic error of ${\sigma }_{{\Omega }_{m_0}}=0.07$ and ${\sigma }_{{\sigma }_8}=0.04$. The mass calibration and statistical quality of the mass tracers are the dominant source of uncertainty.

13 pages, 15 figures

References in corpus (7)

• SPIDERS: the spectroscopic follow-up of X-ray selected clusters of galaxies in SDSS-IV
• Active Galactic Nuclei and their Large-scale Structure: an eROSITA mock catalogue
• LoCuSS: Scaling relations between galaxy cluster mass, gas, and stellar content
• Full-sky photon simulation of clusters and active galactic nuclei in the soft X-rays for eROSITA
• Detection of anti-correlation of hot and cold baryons in galaxy clusters
• Cosmology with clustering anisotropies: disentangling dynamic and geometric distortions in galaxy redshift surveys
• SPIDERS: overview of the X-ray galaxy cluster follow-up and the final spectroscopic data release

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• The Seventeenth Data Release of the Sloan Digital Sky Surveys: Complete Release of MaNGA, MaStar and APOGEE-2 Data
• Mass bias and cosmological constraints from Planck cluster clustering
• On the tomographic cluster clustering as a cosmological probe