(Proposal ID) S16A-060

(PI) Shibuya, Takatoshi

(Proposal Title)
Spectroscopy for Bright LAEs at z~6.6 selected with First HSC-NB Data

(Abstract)
We propose FOCAS and MOIRCS spectroscopy for bright Lyalpha Emitter (LAE) 
candidates at z~6.6 identified with the first released NB921 data of a Hyper 
Supirme-Cam (HSC) survey. The survey area reaches ~23 deg^2 which is >~5 times 
larger than the previous widest NB921 field. As a consequence of our careful 
LAE selection including visual inspection and multi-epoch images for transients
 and moving objects, we identify 6 very rare and bright LAE candidates with 
logL_{Lyalpha}>~43.5 erg s^{-1}. We will carry out spectroscopic follow-up for 
the 6 LAE candidates through Lyalpha detections. Our FOCAS spectroscopy will 
also enable us to check the feature of Lyalpha EW enhancement and to examine 
ISM properties of the bright LAEs. In addition, we will perform MOIRCS 
spectroscopy for the three brightest LAEs in order to investigate whether 
these targets have signatures of Pop III or AGN activity. Our observations 
enlarge a spectroscopic sample of bright LAEs by a factor of >~4, allowing for 
a statistical study on the {Himiko}-like objects, for the first time. This 
first statistical study would provide us with important hints for understanding
 Lyalpha emitting mechanisms, the formation epoch of Pop III stars, physical 
processes of cosmic reionization, and the LAE and AGN evolution.