High-redshift star-forming galaxies and proto-clusters: an insight from clustering studies

One of the best ways to shed light on the possible links between high redshift
proto-clusters and galaxy populations is to investigate the clustering
properties of these latter ones as they provide a powerful
method to constrain halo masses.
In this talk I will present clustering results for galaxies with highly
enhanced star-formation activity (SFR>30 Msun/yr) and will show that,
at redshifts z>~1.5, irrespective of the selection technique and only very
mildly depending on their SFR, they all reside in structures of masses >
10^13.5 Msun, i.e. they are ubiquitously located in over-dense structures
such as proto-clusters. A striking example of the above result is provided by
the distribution of high-redshift star-forming galaxies in the GOODS-South as
more than half of these sources is found to reside in an
unvirialised, filamentary structure, centered at z~2.2, which extends all along the field.  
Our data indicate an enhanced star-forming activity for
the galaxies belonging to the proto-cluster with respect to those in the field.
Finally, we will also show how such structures are a rather common event
in the epoch which coincides with the peak of star formation activity.