The observed infall of galaxies towards the Virgo cluster
Abstract
We examine the velocity field of galaxies around the Virgo cluster induced by its overdensity. A sample of 1792 galaxies with distances from the Tip of the Red Giant Branch, the Cepheid luminosity, the SNIa luminosity, the surface brightness fluctuation method, and the Tully-Fisher relation has been used to study the velocity-distance relation in the Virgocentric coordinates. Attention was paid to some observational biases affected 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 cosmological parameter 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 MT=(2.7 - 8.9) * 1014 M in reasonable agreement with the existing virial mass estimates for the cluster.