(Proposal ID) S14A-018

(PI) Hayashi Masao

(Proposal Title)
 Completing comprehensive survey of star formation and metallicity at z~1.5

(Abstract)
We propose to complete our ongoing FMOS program (S12A-026) to comprehensively 
study star formation and metallicity at z~1.5, since two thirds of the time 
allocated in April 2012 was lost because of poor conditions. Star formation 
activity and metal enrichment can provide us with important clues to understand
 processes of galaxy evolution. However, current measurements of such 
properties for galaxies at z~1.5 have large uncertainties and are biased 
toward massive galaxies due to the lack of spectroscopic samples with major 
nebular emission lines in rest-frame optical wavelengths. We thus plan to 
conduct deep NIR spectroscopy of [OII] emitters at z=1.47 and 1.62 in the 
Subaru Deep Field (SDF), aiming to detect all of Hbeta, [OIII], Halpha, and 
[NII] lines for star-forming galaxies at z~1.5. The SDF is an ideal field 
because the deep multi-band data are perfectly matched to what FMOS requires 
for maximum efficiency. With the full set of major nebular lines, we will 
reveal (1) star formation activity reliably corrected for dust extinction, 
(2)ionization state of HII regions, (3) gas metallicity, and (4) a 
contribution of AGNs, and then investigate a correlation between them. We 
finally aim to understand critical processes which play an important role in 
galaxy evolution.