(Proposal ID) S15B-034

(PI) Tominaga, Nozomu

(Proposal Title)
Spectroscopy of host galaxies of supernovae with shock breakout detection

(Abstract)
Shock breakout is the brightest phenomenon in a normal core-collapse 
supernova (CCSN) and thus is suggested to be a probe of high-z Universe. 
We have started shock breakout surveys with HSC from  the S14A semester. 
Our past HSC observations (S14A-191 and S14B-048) successfully detected 12 
and 11 shock breakout candidates, respectively. While the candidates found 
in the S14A-191 run was spectroscopically followed-up by the FOCAS 
observation (S14B-061), the  11 shock breakout candidates found in the 
S14B-048 run do not have spectroscopic information. The photometric redshifts 
of the host galaxies  with grz or griz photometry indicates that some of the 
host galaxies  are high redshift (z>1). The candidates could be the  highest-z
 normal CCSNe. Therefore, we propose to perform low-resolution  spectroscopic 
observations of their host galaxies. The aims of this  proposal are 
determining the redshift, metallicity, star  formation rate, and dust 
reddening of the host galaxies. This enables to derive properties of normal 
CCSNe at z>1 and clarifies which kind of star formation process is 
characterized by the shock breakout detection. These progresses establish the 
shock breakout as a beachhead to explore the star formation history in the 
high-z Universe.