A distance scale from the infrared magnitude/H I velocity-width relation. II - The Virgo cluster

Recently published 21 cm profiles and new infrared measurements are used to examine the luminosity/velocity-width relation for the Virgo cluster, especially with regard to possible morphological-type dependence. No support is found for the conclusions of Roberts (1978) that at a given luminosity earlier-type galaxies have larger velocity widths. A distance modulus of 30.98 plus or minus 0.09 is deduced for the Virgo cluster; the Hubble ratio for the cluster is found to be 65 plus or minus 4 km per s Mpc. It is concluded that there are no significant discrepancies between the Virgo distance given by the infrared Tully-Fisher (1977) technique and that given by any other method.