The Fornax Cluster VLT Spectroscopic Survey. I - VIMOS spectroscopy of
  compact stellar systems in the Fornax core region
  We present the results of a wide spectroscopic survey aimed at detecting
extragalactic globular clusters (GCs) in the core of the Fornax cluster. About
4500 low resolution spectra (from 4800 to 10000 \AA ) were observed in 25
VLT/VIMOS masks covering the central 1 deg$^{2}$ around the dominant galaxy NGC
1399 corresponding to $\sim$175 kpc galactocentric radius. We describe the
methodology used for data reduction and data analysis. We found a total of 387
unique physical objects (372 GCs and 15 ultra compact dwarfs) in the field
covered by our observations. Most of these objects are associated with NGC
1399, with only 10% likely belonging to other giant galaxies. The new VIMOS
dataset is complementary to the many GC catalogues already present in the
literature and it brings the total number of tracer particles around NGC 1399
to more than 1130 objects. With this comprehensive radial velocity sample we
have found that the velocity dispersion of the GC population (equally for red
and blue GC populations) shows a relatively sharp increase from low velocity
dispersion ($\sim250$-$350$ kms$^{-1}$) to high velocity dispersion
($\sim300$-$400$ kms$^{-1}$) at projected radius of $\approx10$ arcmin
($\sim60$ kpc) from the galaxy centre. This suggests that at a projected radius
of $\approx60$ kpc both blue and red GC populations begin to be governed by the
dominating Fornax cluster potential, rather than by the central NGC 1399 galaxy
potential. This kinematic evidence corroborates similar results found using
surface brightness analysis and planetary nebulae kinematics.
