One of the most puzzling questions in modern astrophysics is how and when the connection between the super-massive black-holes (SMBHs), present at the center of most (if not all) galaxies, and their hosts is formed. My research interests are centered in the observational constraints of such a connection. Importat clues about this fundamental link are necessarily found in the early/young/high-redshift universe, where the formation and growth of SMBH and galaxies take place and where their early connection might take shape. My work focuses specifically in the growing phases of the SMBHs during the AGN episodes. Key points currently explored are:
i) The quantification of the relation between the galaxy AGN activity (nuclear luminosity, accretion rates, black-hole mass, obscuration, radio loudness), not only as a function of the intrinsic properties of the host galaxy (morphology, stellar mass, luminosity, star-formation rates, dust content, etc), but also as a function of its local and large scale environment;
ii) The understanding of the feeding mechanisms operating at different scales that bring gas and dust near the SMBH, ultimately triggering nuclear emission in AGN.
iii) To oprovide the means for a more accurate census of QSOs in the early universe (at z>5), in terms of larger number of QSO per redshift and magnitude interval over a wide absolute magnitude range. This will place further constraints on: a) the AGN contribution to the re-ionization epoch, b) the physical conditions in the early universe, c) models of galaxy & BH formation, and BH growth.