Open AccessThe power spectrum amplitude from clusters revisited: σ 8 using simulations with pre‐heating and cooling
Author(s) -
Viana Pedro T. P.,
Kay Scott T.,
Liddle Andrew R.,
Muanwong Orrarujee,
Thomas Peter A.
Publication year - 2003
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-2966.2003.07088.x
Subject(s) - physics , amplitude , astrophysics , galaxy cluster , radiative cooling , spectral density , cosmology , anisotropy , scaling , cluster (spacecraft) , monte carlo method , cosmic microwave background , matter power spectrum , radiative transfer , normalization (sociology) , galaxy , computational physics , dark energy , quantum mechanics , statistics , geometry , mathematics , sociology , computer science , anthropology , programming language
The amplitude of density perturbations, for the currently‐favoured ΛCDM cosmology, is constrained using the observed properties of galaxy clusters. The catalogue used is that of Ikebe et al. The relation of cluster temperature to mass is obtained via N ‐body/hydrodynamical simulations including radiative cooling and pre‐heating of cluster gas, which we have previously shown to reproduce well the observed temperature–mass relation in the innermost parts of clusters. We generate and compare mock catalogues via a Monte Carlo method, which allows us to constrain the relation between X‐ray temperature and luminosity, including its scatter, simultaneously with cosmological parameters. We find a luminosity–temperature relation in good agreement with the results of Ikebe et al., while for the matter power spectrum normalization, we find σ 8 = 0.78 +0.30 −0.06 at 95 per cent confidence for Ω 0 = 0.35 . Scaling to the Wilkinson Microwave Anisotropy Probe central value of Ω 0 = 0.27 would give a best‐fitting value of σ 8 ≃ 0.9 .