(Proposal ID) S11A-066

(PI) Akiyama, Masayuki

(Proposal Title)
A Search for Heavily-obscured AGNs among Galaxies at z~1.5

(Abstract)
Hard X-ray surveys with various depth revealed the cosmic evolution of the 
luminosity function of un-obscured and mildly-obscured AGNs. However, recently 
large number of heavily-obscured AGNs, so-called Compton-thick AGNs, which can 
be missed in the hard X-ray surveys, are discovered with [OIII]-emission line 
survey in the local universe. It is suggested that still significant portion 
of the accretion growth history of SMBHs is not uncovered yet. Here, in order 
to determine the number density of heavily-obscured AGNs systematically at z = 
1.3 - 1.6, we propose to conduct rest-frame optical emission-line survey for a 
volume-limited massive galaxies in MOIRCS Deep Survey (GOODS-North) region with
 FMOS in a similar manner to SDSS for galaxies in the local universe. Using 
deep X-ray and MIR data in the region, heavily-obscured AGNs can be identified 
among the optical-line-selected AGNs. Combining with the X-ray selected AGNs 
in the same field, we can determine the fraction of heavily-obscured AGNs and 
the fraction of luminous AGNs among massive galaxies at redshifts where AGN-
activity peaks. Thanks to the unique capabilities of FMOS, we can efficiently 
survey large number of massive galaxies in the redshift range for the first 
time.