| Abstract |
Aims: This work aims to provide a new mass estimate for the Fornax cluster and the Fornax-Eridanus complex, avoiding methods like the virial or fits of the X-ray emission profile, which assume that the system is in equilibrium. This is probably not the case for Fornax, because it is still in process of formation.
Methods: Our mass estimate is based on determination of the zero-velocity surface, which, in the context of the spherical infall model, permits an evaluation of the total mass inside such a surface. The zero-velocity surface radius R0 was estimated either by a running median procedure or by fitting the data to the velocity field expected from the spherical model, including effects of the cosmological constant. The velocity field in a region within 20 Mpc of the Fornax center was mapped using a list of 109 galaxies whose distances have an average accuracy of 0.31 mag in their distance modulus.
Results: Our analysis indicates that the mass of the Fornax cluster itself is [0.40-3.32] × 1014 M☉ inside a radius of [2.62-5.18] Mpc while the mass inside [3.88-5.60] Mpc, corresponding to the Fornax-Eridanus complex, is [1.30-3.93] × 1014 M☉. The catalog is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/532/A104 |
