2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/106822Deep X-ray surveys are providing crucial information on the evolution of AGN and galaxies. We review some of the latest results based on the X-ray spectral analysis of the sources detected in the Chandra Deep Field South, namely: i) constraints on obscured accretion; ii) constraints on the missing fraction of the X-ray background; iii) the redshift distribution of Compton-thick sources and TypeII QSO; iv) the detection of star formation activity in high-z galaxies through stacking techniques; v) the detection of large scale structure in the AGN distribution and its effect on nuclear activity. Such observational findings are consistent with a scenario where nuclear activity and star formation processes develop together in an anti-hierarchical fashion.8 pages, 10 Figures, to be published in Mem SAIt, Proceedings of the Workshop on "AGN and Galaxy Evolution", held in the Specola Vaticana, Castel Gandolfo, Italy - October 2005Astrophysicstext