The Hubble space telescope key project on the extragalactic distance scale. XXVII. A derivation of the Hubble constant using the fundamental plane and Dn-σ relations in Leo I, Virgo, and Fornax

Abstract

Using published photometry and spectroscopy, we construct the fundamental plane and Dn-σ relations in Leo I, Virgo, and Fornax. The published Cepheid period-luminosity (PL) relations to spirals in these clusters fixes the relation between angular size and metric distance for both the fundamental plane and Dn-σ relations. Using the locally calibrated fundamental plane, we infer distances to a sample of clusters with a mean redshift of cz ≈ 6000 km s-1, and derive a value of H0 = 78 ± 5 ± 9 km s-1 Mpc-1 (random and systematic errors, respectively) for the local expansion rate. This value includes a correction for depth effects in the Cepheid distances to the nearby clusters, which decreased th..