The Hubble Constant from SZE Measurements in Low-Redshift Clusters

We present a determination of the Hubble constant from measurements of the Sunyaev-Zeldovich Effect (SZE) in an orientation-unbiased sample of 7 z < 0.1 galaxy clusters. With improved X-ray models and a more accurate 32-GHz calibration, we obtain H_O = 64+14-11 +/- 14_sys km/s/Mpc. for a standard CDM cosmology, or 66+14-11 +/- 15_sys km/s/Mpc for a flat LambdaCDM cosmology. The random uncertainty in this result is dominated by intrinsic CMB anisotropies, and the systematic uncertainty is chiefly due to uncertainties in the X-ray spectral models. The implications of this result and future prospects for the method are discussed.