Constraining the dark energy with galaxy clusters X-ray data

J. A. S. Lima; J. V. Cunha; J. S. Alcaniz

doi:10.1103/PhysRevD.68.023510

paper

Constraining the dark energy with galaxy clusters X-ray data

arXiv:astro-ph/0303388 · doi:10.1103/PhysRevD.68.023510

Abstract

The equation of state characterizing the dark energy component is constrained by combining Chandra observations of the X-ray luminosity of galaxy clusters with independent measurements of the baryonic matter density and the latest measurements of the Hubble parameter as given by the HST key project. By assuming a spatially flat scenario driven by a "quintessence" component with an equation of state $p_{x} = ω ρ_{x}$ we place the following limits on the cosmological parameters $ω$ and $Ω_{m}$ : (i) $- 1 \leq ω \leq - 0.55$ and $Ω_{m} = 0.3 2_{- 0.014}^{+ 0.027}$ (1 $σ$ ) if the equation of state of the dark energy is restricted to the interval $- 1 \leq ω < 0$ (\emph{usual} quintessence) and (ii) $ω = - 1.2 9_{- 0.792}^{+ 0.686}$ and $Ω_{m} = 0.3 1_{- 0.034}^{+ 0.037}$ ( $1 σ$ ) if $ω$ violates the null energy condition and assume values $< - 1$ (\emph{extended} quintessence or ``phantom'' energy). These results are in good agreement with independent studies based on supernovae observations, large-scale structure and the anisotropies of the cosmic background radiation.

6 pages, 4 figures, LaTeX

Constraining the dark energy with galaxy clusters X-ray data

Abstract

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