Investigations of the Local Supercluster Velocity Field II. A study using Tolman-Bondi solution and galaxies with accurate distances from the Cepheid PL-relation

Abstract

A sample of 32 galaxies with accurate distance moduli from the Cepheid PL-relation (Lanoix 1999) has been used to study the dynamical behaviour of the Local (Virgo) supercluster. We used analytical Tolman-Bondi (TB) solutions for a spherically symmetric density excess embedded in the Einstein-deSitter universe (q_0=0.5). Using 12 galaxies within Theta=30 degr from the centre we found a mass estimate of 1.62M_virial for the Virgo cluster. This agrees with the finding of Teerikorpi et al. (1992} that TB-estimate may be larger than virial mass estimate from Tully & Shaya (1984). Our conclusions do not critically depend on our primary choice of the global H_0=57 km/s/Mpc established from SNe Ia (Lanoix 1999). The remaining galaxies outside Virgo region do not disagree with this value. Finally, we also found a TB-solution with the H_0 and q_0 cited yielding exactly one virial mass for the Virgo cluster.