The SBF Survey of Galaxy Distances. I. Sample Selection, Photometric Calibration, and the Hubble Constant

Abstract

We describe a program of surface brightness fluctuation (SBF) measurements for determining galaxy distances. This paper presents the photometric calibration of our sample and of SBF in general. Basing our zero point on observations of Cepheid variable stars, we find that the absolute SBF magnitude in the Kron-Cousins I band correlates well with the mean (V-I)o color of a galaxy according to M_Ibar = (-1.74 +/- 0.07) + (4.5 +/- 0.25) [ (V-I)o - 1.15 ] for 1.0 < (V-I) < 1.3. This agrees well with theoretical estimates from stellar population models. Comparisons between SBF distances and a variety of other estimators, including Cepheid variable stars, the Planetary Nebula Luminosity Function (PNLF), Tully-Fisher (TF), Dn-sigma, SNII, and SNIa, demonstrate that the calibration of SBF is universally valid and that SBF error estimates are accurate. The zero point given by Cepheids, PNLF, TF (both calibrated using Cepheids), and SNII is in units of Mpc; the zero point given by TF (referenced to a distant frame), Dn-sigma and SNIa is in terms of a Hubble expansion velocity expressed in km/s. Tying together these two zero points yields a Hubble constant of H_0 = 81 +/- 6 km/s/Mpc. As part of this analysis, we present SBF distances to 12 nearby groups of galaxies where Cepheids, SNII, and SNIa have been observed.