(Proposal ID) S16A-076

(PI) Matsuoka, Yoshiki

(Proposal Title)
Spectroscopic Identification of HSC-SSP Quasars at z > 6

(Abstract)
High-z quasars are an important probe of the distant universe, for the early 
growth of supermassive black holes (SMBHs), the cosmic reionization, and 
evolution of host galaxies, among others. We are now starting a ground-breaking
 survey for z > 6 quasars using the exquisite imaging data provided by the 
Hyper Suprime-Cam (HSC) Subaru Strategic Program (SSP) survey. We will probe 
the most distant quasars down to ~2 mag lower luminosity (M_{1450} < -22 mag) 
than any previous survey, and will increase the number of known z > 6 quasars 
by almost an order of magnitude.  Here we propose FOCAS spectroscopy of 16 
quasar candidates selected from the latest HSC-SSP data. They are securely 
detected in more than a single band and have significant Bayesian probability 
of being z > 6 quasars. We will observe their spectra around 0.75 - 1.0 mum in 
order to capture the characteristic features of high-z quasars. The purpose of 
this program is (i) to achieve the first discovery of HSC high-z quasars and 
get a new constraint on the faint end of their luminosity function, and (ii) 
to evaluate our grand survey strategy. It will be an important milestone 
towards our final goal of better understanding the formation and evolution of 
SMBHs and galaxies in the early universe.