Metallicity in Narrow Line Regions go High-z Type-2 AGN
The physics and demographics of high redshift obscured active galactic nuclei is still scarcely studied, and new samples of such objects, selected with different techniques, can provide useful insights into their physical nature. A sample of 90 narrow-line with 1.5< z < 3.0 was selected from the zCOSMOS-deep galaxy sample by detection of the high-ionization CIV 1549A emission line. The presence of this feature in a galaxy spectrum is indicative of nuclear activity, and the selection effectiveness has been also confirmed by ultraviolet emission line diagnostic diagrams. Taking advantage of the large amount of data available in the COSMOS field, the properties of the \civ-selected Type 2 AGN were analyzed, focusing on their host galaxies, X-ray emission, and UV emission line characteristics. Finally, the physical properties of the ionized gas in the Narrow Line Region have been investigated, combining the analysis of strong UV emission lines with the prediction from photoionization models.