We present results of an extensive spectroscopic survey of Subgiant stars in the stellar system \omega Centauri .
Using infrared Ca II triplet lines , we derived metallicities and radial velocities for more than 250 stars belonging to different stellar populations of the system .
We find that the most metal rich component , the anomalous Sub Giant Branch ( SGB-a ) , has a metallicity of [ Fe/H ] \sim -0.6 fully compatible with that determined along the anomalous Red Giant Branch ( RGB-a ) .
Our analysis suggests that the age of this component and of the other metal-intermediate ( -1.4 ~ { } < ~ { } [ Fe / H ] ~ { } < ~ { } -1.0 ) stellar populations of the system are all comparable to that of the dominant metal poor population within 2 Gyr , regardless of any choice of helium abundance .
These results impose severe constraints on the time-scale of the enrichment process of this stellar system , excluding the possibility of an extended star formation period .
The radial velocity analysis of the entire sample demonstrates that only metal-intermediate populations are kinematically cooler than the others .