(Proposal ID) S12B-080

(PI) Daddi, Emanuele

(Proposal Title)
Exposing high-z obscured AGNs in the deepest IR/X-rays surveys

(Abstract)
The identification and study of the elusive population of high redshift 
obscured AGNs is an important step towards understanding the fundamental phase 
of black hole growth in the young universe. Here we propose NIR spectroscopy 
with MOIRCS to confirm and characterize candidate high-z obscured/Compton-
thick AGNs found in the deepest Herschel and X-ray surveys. The sample, 
designed to cover a range of redshifts (1.5 < z < 4), is selected from the 
GOODS field by use of Herschel+Spitzer (MIR to FIR colors and the presence of 
power-law MIR emission) and X-ray spectral properties from XMM and Chandra. 
The MOIRCS data are crucial to fully confirm and exploit our sample. The 
specific science goals include (a) obtaining independent AGN classifications 
and luminosities via rest-frame optical spectroscopy;  (b) testing for the 
expected strong outflows in these high bolometric luminosity QSOs; (c) 
spectroscopically confirming redshifts of objects which currently have only 
z_phot. In the larger picture, this study will put stronger constraints on the 
number density of Compton-thick AGNs and on the evolution of supermassive 
black holes and their host galaxies.