(Proposal ID) S15B-070

(PI) Matsuoka, Yoshiki

(Proposal Title)
Spectroscopic identification of HSC-SSP high-z quasar candidates

(Abstract)
High-redshift quasars are an important probe of the distant universe. They 
enable observational studies of the early growth of supermassive black holes 
(SMBHs), the cosmic reionization, and the chemical enrichment of host galaxies 
in a complementary way to other types of objects. We are now starting a new 
ground-breaking survey for high-z (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 10 quasar candidates selected from the early HSC-SSP data. 
We will observe their spectra around 0.75 - 1.0 mu m 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.