The observed infall of galaxies towards the Virgo cluster

We examine the velocity field of galaxies around the Virgo cluster induced by its overdensity. We have studied the velocity-distance relation in Virgocentric coordinates using a sample of 1792 galaxies with distances from the tip of the Red Giant Branch, the Cepheid luminosity, the luminosity of type Ia supernovae, the surface brightness fluctuation method and the Tully-Fisher relation. Attention was paid to some observational biases affecting the Hubble flow around Virgo. We estimate the radius of the zero-velocity surface for the Virgo cluster to be within 5.0-7.5 Mpc, corresponding to 17-26° at the mean cluster distance of 17.0 Mpc. In the case of spherical symmetry with the cosmological parameter Ω_m = 0.24 and the age of the Universe T₀ = 13.7 Gyr, it yields the total mass of the Virgo cluster to be within M_T = (2.7-8.9) × 10¹⁴ M_solar in reasonable agreement with the existing virial mass estimates for the cluster.