2000ApJ...533...38R

We determine the distances to the z≃0.55 galaxy clusters MS 0451.6-0305 and Cl 0016+16 from a maximum-likelihood joint fit to 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. For an Ω_M=0.3, Ω_Λ=0.7 cosmology, these distances imply a Hubble constant of 63⁺¹²⁺²¹_–9–21 km.s^–1.Mpc^–1, where the uncertainties correspond to statistical followed by systematic at 68% confidence. The best-fit H₀ is 57 km.s^–1.Mpc^–1 for an open (Ω_M=0.3) universe and 52 km.s^–1.Mpc^–1 for a flat (Ω_M=1) universe.