Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-09-29
Astronomy and Astrophysics
Astrophysics
5 pages, 2 figures, final version, accepted for publication in A&A
Scientific paper
We investigate the cosmological test based on the evolution of the gas fraction in X-ray galaxy clusters and the stability of the cosmological parameters derived from it. Using a sample of distant clusters observed by XMM-Newton and Chandra, and comparing their gas fraction at different radii to the gas fraction observed for nearby clusters, we have determined the likelihood functions for $\Omega_m$ in a flat universe and the confidence contours in the $\Omega_m-\Omega_{\Lambda}$ plane. Results obtained at the virial radius point to a high matter density Universe, while for inner radii the $\Omega_m$ parameter obtained tends to decrease, reaching values compatible with the concordance model. The analysis allows us to conclude that this test provides ambiguous results due to the complex structure of the ICM that induces a dependence of the gas fraction with temperature, radius, and redshift which cannot be accounted by a self similar argument expected in pure gravitational heating of the ICM. The use of gas fraction in X-ray clusters to constrain cosmological parameters seems therefore to be compromised until a better understanding of the ICM physics and the ability to obtain observations of better quality up to the virial radius are achieved.
Blanchard Alain
Ferramacho Luis
No associations
LandOfFree
Gas mass fraction from XMM-Newton and Chandra high redshift clusters and its use as a cosmological test does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Gas mass fraction from XMM-Newton and Chandra high redshift clusters and its use as a cosmological test, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gas mass fraction from XMM-Newton and Chandra high redshift clusters and its use as a cosmological test will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-183869