Mar 15 – 20, 2020
Europe/Berlin timezone

Cosmological constraints from CODEX galaxy clusters spectroscopically confirmed by SDSS-IV SPIDERS DR16

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Mr Jacob Ider Chitham (MPE)


We present a cosmological analysis based on the properties of X-ray selected clusters of galaxies from the CODEX survey, which have been spectroscopically validated as part of the SPIDERS programme within SDSS DR16. The sample contains a total of 2740 clusters over an area of 5,300deg$^{2}$, making it the largest spectroscopic cluster catalogue ever constructed. Optical richness is used as a proxy for the cluster mass, and the combination of X-ray, optical and spectroscopic information ensures that only confirmed virialised systems are considered. Clusters are binned in redshift, $z \in \left[0.1, 0.6\right)$ and optical richness, $\lambda \in \left[20, 244\right)$ and the counts in each bin are modelled as a function of cosmological and scaling relation parameters. A high-purity sub-sample of 1017 clusters is used in the fiducial analysis and best fit cosmological parameters are found to be $\Omega_0=0.31^{+0.04}_{-0.03}$ and $\sigma_8=0.72^{+0.03}_{-0.03}$. These results are consistent with previous measurements in the literature and the precision is comparable to other state-of-the-art cluster cosmology experiments.

Primary authors

Mr Jacob Ider Chitham (MPE) Johan Comparat (MPE) Alexis Finoguenov (University of Helsinki) Nicolas Clerc (IRAP) Charles Kirkpatrick (University of Helsinki) Sanna Damsted (University of Helsinki) Antti Kukkola Rafaela Capasso (University of Stokholm) Paul Nandra (MPE) Andrea Merloni (MPE) Esra Bulbul (MPE) Donald Schneider (Pennsylvania State University) Joel Brownstein (University of Utah)

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