Determination of the Cosmic Distance Scale from SunyaevZel'dovich Effect and Chandra XRay Measurements of HighRedshift Galaxy Clusters
Abstract
We determine the distance to 38 clusters of galaxies in the redshift range 0.14<=z<=0.89 using Xray data from Chandra and SunyaevZeldovich effect (SZE) data from the Owens Valley Radio Observatory and the BerkeleyIllinoisMaryland Association interferometric arrays. The cluster plasma and dark matter distributions are analyzed using a hydrostatic equilibrium model that accounts for radial variations in density, temperature, and abundance, and the statistical and systematic errors of this method are quantified. The analysis is performed via a Markov chain Monte Carlo technique that provides simultaneous estimation of all model parameters. We measure a Hubble constant of H_{0}=76.9^{+3.9}_{3.4}^{+10.0}_{8.0} km s^{1} Mpc^{1} (statistical followed by systematic uncertainty at 68% confidence) for an Ω_{M}=0.3, Ω_{Λ}=0.7 cosmology. We also analyze the data using an isothermal βmodel that does not invoke the hydrostatic equilibrium assumption and find H_{0}=73.7^{+4.6}_{3.8}^{+9.5}_{7.6} km s^{1} Mpc^{1} to avoid effects from cool cores in clusters, we repeated this analysis excluding the central 100 kpc from the Xray data and find H_{0}=77.6^{+4.8}_{4.3}^{+10.1}_{8.2} km s^{1} Mpc^{1} (statistical followed by systematic uncertainty at 68% confidence). The consistency between the models illustrates the relative insensitivity of SZE/Xray determinations of H_{0} to the details of the cluster model. Our determination of the Hubble parameter in the distant universe agrees with the recent measurement from the Hubble Space Telescope Key Project that probes the nearby universe.
 Publication:

The Astrophysical Journal
 Pub Date:
 August 2006
 DOI:
 10.1086/505291
 arXiv:
 arXiv:astroph/0512349
 Bibcode:
 2006ApJ...647...25B
 Keywords:

 Cosmology: Cosmic Microwave Background;
 Cosmology: Distance Scale;
 XRays: Galaxies: Clusters;
 Astrophysics
 EPrint:
 ApJ submitted (revised version)