Constraining the cosmological parameters with the gas mass fraction in local and z>0.7 Galaxy Clusters

Details Constraining the cosmological parameters with the gas mass fraction in local and z>0.7 Galaxy Clusters Constraining the cosmological parameters with the gas mass fraction in local and z>0.7 Galaxy Clusters

2002-11-14

arxiv.org/abs/astro-ph/0211335v3

Astron.Astrophys.398:879-890,2003

Astronomy and Astrophysics

Astrophysics

12 pages, A&A in press. Equation 7 has been corrected

Scientific paper

10.1051/0004-6361:20021706

We present a study of the baryonic fraction in galaxy clusters aimed at constraining the cosmological parameters Omega_m, Omega_Lambda and the ratio between the pressure and density of the ``dark'' energy, w. We use results on the gravitating mass profiles of a sample of nearby galaxy clusters observed with the BeppoSAX X-ray satellite (Ettori, De Grandi, Molendi 2002) to set constraints on the dynamical estimate of Omega_m. We then analyze Chandra observations of a sample of eight distant clusters with redshift in the range 0.72 and 1.27 and evaluate the geometrical limits on the cosmological parameters Omega_m, Omega_Lambda and w by requiring that the gas fraction remains constant with respect to the look-back time. By combining these two independent probability distributions and using a priori distributions on both Omega_b and H0 peaked around primordial nucleosynthesis and HST-Key Project results respectively, we obtain that, at 95.4 per cent level of confidence, (i) w < -0.49, (ii) Omega_m = 0.34^+0.11_-0.05, Omega_Lambda = 1.30^+0.44_-1.09 for w=-1 (corresponding to the case for a cosmological constant), and (iii) Omega_m = 1-Omega_Lambda = 0.33^+0.07_-0.05 for a flat Universe. These results are in excellent agreement with the cosmic concordance scenario which combines constraints from the power spectrum of the Cosmic Microwave Background, the galaxy and cluster distribution, the evolution of the X-ray properties of galaxy clusters and the magnitude-redshift relation for distant type Ia supernovae. By combining our results with the latter method we further constrain Omega_Lambda =0.94^+0.28_-0.32 and w < -0.89 at the 2 sigma level.

Affiliated with

Also associated with

No associations

Rating

Constraining the cosmological parameters with the gas mass fraction in local and z>0.7 Galaxy Clusters 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 Constraining the cosmological parameters with the gas mass fraction in local and z>0.7 Galaxy Clusters, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Constraining the cosmological parameters with the gas mass fraction in local and z>0.7 Galaxy Clusters will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-473339