http://arxiv.org/abs/2002.11907
We derive cosmological constraints on the matter density, $\Omega_m$, and the amplitude of fluctuations, $\sigma_8$, using $\mathtt{GalWCat19}$, a catalog of 1800 galaxy clusters we identified in the Sloan Digital Sky Survey-DR13 spectroscopic data set using our GalWeight technique to determine cluster membership (Abdullah et al. 2018; Abdullah et al. 2020). By analyzing a subsample of 843 clusters in the redshift range $0.01 \leq z \leq 0.125$ with virial masses of $M\geq 0.8\times10^{14}$ $h^{-1} \ M_{\odot}$, we obtain $\Omega_m=0.305^{+0.037}{-0.042}$ and $\sigma_8=0.810^{+0.053}{-0.056}$, with a cluster normalization relation of $\sigma_8= 0.44 \Omega_m^{-0.52}$. There are several unique aspects to our approach: we use the largest spectroscopic data set currently available, and we assign membership using the GalWeight technique which we have shown to be very effective at simultaneously maximizing the number of {\it{bona fide}} cluster members while minimizing the number of contaminating interlopers. Moreover, rather than employing scaling relations, we calculate cluster masses individually using the virial mass estimator. Since $\mathtt{GalWCat19}$ is a low-redshift cluster catalog we do not need to make any assumptions about evolution either in cosmological parameters or in the properties of the clusters themselves. Our constraints on $\Omega_m$ and $\sigma_8$ are consistent and very competitive with those obtained from non-cluster abundance cosmological probes such as Cosmic Microwave Background (CMB), Baryonic Acoustic Oscillation (BAO), and supernovae (SNe). The joint analysis of our cluster data with Planck18+BAO+Pantheon gives $\Omega_m=0.310^{+0.013}{-0.010}$ and $\sigma_8=0.810^{+0.010}{-0.013}$.
M. Abdullah, A. Klypin and G. Wilson
Fri, 28 Feb 20
44/49
Comments: 12 pages, 7 figures
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