Spectroscopic hint of a cold stream in the direction of the globular
  cluster NGC 1851
  We present the results of a spectroscopic survey performed in the outskirts
of the globular cluster NGC1851 with VIMOS@VLT. The radial velocities of 107
stars in a region between 12' and 33' around the cluster have been derived. We
clearly identify the cluster stellar population over the entire field of view,
indicating the presence of a significant fraction of stars outside the tidal
radius predicted by King models. We also find tentative evidence of a cold
(sigma_v< 20 km/s) peak in the distribution of velocities at v_r~180 km/s
constituted mainly by Main Sequence stars whose location in the color-magnitude
diagram is compatible with a stream at a similar distance of this cluster. If
confirmed, this evidence would strongly support the extra-Galactic origin of
this feature.
