| Abstract | A large sample (n = 256) of spiral galaxies with type Sab to Sd, having corrected apparent magnitudes BT0 and 21-cm H I velocities and line widths is used to study the variation of the Hubble constant derived from the Bottinelli et al. version of the Tully-Fisher (TF) relation with respect to kinematic distances, Dv, in an infall model toward Virgo. It is shown that (before or after correction of the type effect) the Hubble constant increases approximately from log H0 ≅ 1.78 at Dv = 250 km s-1 to log H0 ≅ 2.08 at Dv = 5000 km s-1. Different possible explanations including the galactic extinction, the Malmquist bias, the slope of the TF relation, and an inadequate model are briefly explored. |
