The Fornax Cluster VLT Spectroscopic Survey IV -- Cold kinematical
  substructures in the Fornax core from COSTA
  The COld STream finder Algorithm (COSTA) is a novel algorithm to find streams
in the phase space of planetary nebulae (PNe) and globular cluster (GCs)
populations. COSTA isolates groups of particles with small velocity dispersion,
using an iterative sigma-clipping over a defined number of neighbor particles.
We have applied COSTA to a catalog of about 2000 PNe and GCs from the Fornax
Cluster VLT Spectroscopic Survey (FVSS), within 200 kpc from the cluster core,
to detect cold substructures and characterize their kinematics. We have found
13 cold substructures, with velocity dispersion ranging from 20 to 100
kms^{-1}, which are likely associated either to large galaxies or to
ultra-compact dwarf (UCD) galaxies in the Fornax core. These streams show a
clear correlation of their luminosity with the internal velocity dispersion,
and their surface brightness with size and distance from the cluster center
that are compatible with dissipative processes producing them. However, we
cannot exclude that some of these substructures have formed by violent
relaxation of massive satellites finally merged into the central galaxy. Among
these substructures we have: a stream connecting NGC1387 to the central galaxy,
NGC1399, previously reported in literature; a new giant stream produced by the
interaction of NGC1382 with NGC1380 and possibly NGC1381; a series of streams
kinematically connected to nearby ultra compact dwarf galaxies; clumps of
tracers with no clear kinematical association to close cluster members. We show
evidence for a variety of cold substructure predicted in simulations. Most of
the streams are kinematically connected to UCDs, supporting the scenario that
they can be remnants of disrupted dwarf systems. [abridged]
