... groups[*]
Based on observations collected at the European Southern Observatory, Chile, through the proposals 073.C-0834(A) and 074.C-0323(A).
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
...[*]
Figure 6 is only available in electronic form at http://www.aanda.org
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Copyright ESO 2007