Determining the cosmic distance scale from interferometric measurements of the Sunyaev-Zeldovich effect.
REESE E.D., CARLSTROM J.E., JOY M., MOHR J.J., GREGO L. and HOLZAPFEL W.L.
Abstract (from CDS):
We determine the distances to 18 galaxy clusters with redshifts ranging from z∼0.14 to 0.78 from a maximum likelihood joint analysis of 30 GHz interferometric Sunyaev-Zeldovich effect (SZE) and X-ray observations. We model the intracluster medium (ICM) using a spherical isothermal β model. We quantify the statistical and systematic uncertainties inherent to these direct distance measurements, and we determine constraints on the Hubble parameter for three different cosmologies. These distances imply a Hubble constant of 60+4+13–4–18km.s–1 Mpc–1 for an ΩM=0.3, ΩΛ=0.7 cosmology, where the uncertainties correspond to statistical followed by systematic at 68% confidence. With a sample of 18 clusters, systematic uncertainties clearly dominate. The systematics are observationally approachable and will be addressed in the coming years through the current generation of X-ray satellites (Chandra and XMM-Newton) and radio observatories (Owens Valley Radio Observatory, Berkeley-Illinois-Maryland Association, and Very Large Array). Analysis of high-redshift clusters detected in future SZE and X-ray surveys will allow a determination of the geometry of the universe from SZE-determined distances.