A New Dynamical Mass Measurement for the Virgo Cluster using the Radial
  Velocity Profile of the Filament Galaxies
  The radial velocities of the galaxies in the vicinity of a cluster shows
deviation from the pure Hubble flow due to their gravitational interaction with
the cluster. According to a recent study of Falco et al. (2014) based on a
high-resolution N-body simulation, the radial velocity profile of the galaxies
located at distances larger than three times the virial radius of a neighbor
cluster can be well approximated by a universal formula and could be
reconstructed from direct observables provided that the galaxies are
distributed along one dimensional filament. They suggested an algorithm for the
estimation of the dynamic mass of a cluster $M_{\rm v}$ by fitting the
universal formula from the simulation to the reconstructed radial velocity
profile of the filament galaxies around the cluster from observations. We apply
the algorithm to two narrow straight filaments (called the Filament A and B)
that were identified recently by Kim et al. (2015) in the vicinity of the Virgo
cluster from the NASA-Sloan-Atlas catalog. The dynamical mass of the Virgo
cluster is estimated to be $M_{\rm
v}=(0.84^{+2.75}_{-0.51})\times10^{15}\,h^{-1}M_{\odot}$ and $M_{\rm v}=
(3.24^{+4.99}_{-1.31})\times 10^{15}\,h^{-1}M_{\odot}$ for the cases of the
Filament A and B, respectively. We discuss observational and theoretical
systematics intrinsic to the method of Falco et al. (2014) as well as the
physical implication of the final results.
