  Recently, intense emission from nebular C III] and C IV emission lines have
been observed in galaxies in the epoch of reionization ($z>6$) and have been
proposed as the prime way of measuring their redshift and studying their
stellar populations. These galaxies might represent the best examples of cosmic
reionizers, as suggested by recent low-z observations of Lyman Continuum
emitting galaxies, but it is hard to directly study the production and escape
of ionizing photons at such high redshifts. The ESO spectroscopic public survey
VANDELS offers the unique opportunity to find rare examples of such galaxies at
cosmic noon ($z\sim 3$), thanks to the ultra deep observations available. We
have selected a sample of 39 galaxies showing C IV emission, whose origin
(after a careful comparison to photoionization models) can be ascribed to star
formation and not to AGN. By using a multi-wavelength approach, we determine
their physical properties including metallicity and ionization parameter and
compare them to the properties of the parent population to understand what are
the ingredients that could characterize the analogs of the cosmic reionizers.
We find that C IV emitters are galaxies with high photons production efficiency
and there are strong indications that they might have also large escape
fraction: given the visibility of C IV in the epoch of reionization this could
become the best tool to pinpoint the cosmic reioinzers.
