Associate narrow absorbers (Valentina D'Odorico)

We will study the co-evolution of galaxies and black holes by measuring metallicities in the interstellar media of the quasar host galaxies. This measure can be carried out using narrow absorption lines with redshifts close to the QSO redshift, the so-called associated absorption lines (AALs). Super-solar metallicities have been measured and the observed abundances are generally reproduced by models of galaxy-AGN evolution, although samples are limited to a few systems at z~2-3 (e.g. D'Odorico et al. 2004). Measurement based on broad emission lines shows that the metallicity of AGN is very high (super-solar) and it does not show any evidence of evolution with redshift out to z = 6.4 (e.g., Maiolino 2009, arXiv:0902.4761). We want to verify this trend with AALs at z > 3:5. To select suitable systems we need intermediate resolution and a large spectral coverage, which only X-shooter is providing at present. The best candidates will then be followed up with UVES to resolve the narrow metal lines. For QSOs where the emission lines lie in transmission windows in the IR we will also be able to simultaneously determine the chemical abundances from the emission lines and from the AALs. This data set will also provide a uniquely large AAL sample to check for time variability of absorption lines (since most of these QSOs have been previously observed with at least R ~ 2000 resolution, e.g. in SDSS) as a test for outflow lines. Accurate measurements of the quasar systemic velocity based on the narrow forbidden emission lines falling in the NIR (e.g., [O II] 3727, [O III] 5007) is another important new contribution to AAL studies to determine their halo/outflow/inflow origins.