Mon. Not. R. Astron. Soc., 471, 1370-1389 (2017/October-3)
HICOSMO: cosmology with a complete sample of galaxy clusters - II. Cosmological results.
SCHELLENBERGER G. and REIPRICH T.H.
Abstract (from CDS):
The X-ray bright, hot gas in the potential well of a galaxy cluster enables systematic X-ray studies of samples of galaxy clusters to constrain cosmological parameters. HIFLUGCS consists of the 64 X-ray brightest galaxy clusters in the Universe, building up a local sample. Here, we utilize this sample to determine, for the first time, individual hydrostatic mass estimates for all the clusters of the sample and, by making use of the completeness of the sample, we quantify constraints on the two interesting cosmological parameters, Ωm and σ8. We apply our total hydrostatic and gas mass estimates from the X-ray analysis to a Bayesian cosmological likelihood analysis and leave several parameters free to be constrained. We find Ωm = 0.30 ± 0.01 and σ8 = 0.79 ± 0.03 (statistical uncertainties, 68 per cent credibility level) using our default analysis strategy combining both a mass function analysis and the gas mass fraction results. The main sources of biases that we correct here are (1) the influence of galaxy groups (incompleteness in parent samples and differing behaviour of the Lx-M relation), (2) the hydrostatic mass bias, (3) the extrapolation of the total mass (comparing various methods), (4) the theoretical halo mass function and (5) other physical effects (non-negligible neutrino mass). We find that galaxy groups introduce a strong bias, since their number density seems to be over predicted by the halo mass function. On the other hand, incorporating baryonic effects does not result in a significant change in the constraints. The total (uncorrected) systematic uncertainties (∼20 per cent) clearly dominate the statistical uncertainties on cosmological parameters for our sample.
© 2017 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society
galaxies: clusters: intracluster medium - cosmological parameters - large-scale structure of Universe - cosmology: observations - X-rays: galaxies: clusters - X-rays: galaxies: clusters
View the reference in ADS
To bookmark this query, right click on this link: simbad:2017MNRAS.471.1370S and select 'bookmark this link' or equivalent in the popup menu