(Proposal ID) S11B-031

(PI) Hayashi, Masao

(Proposal Title)
The nature of [OII] emitters in and around three frontier clusters at z ~ 1.5

(Abstract)
We propose a NIR spectroscopy of [OII] emission line galaxies in the three 
frontier clusters and its surrounding groups at z=1.46-1.62 with MOIRCS. We 
aim to detect their major nebular emission lines of H alpha, H beta, [OIII], 
and [NII], which provide us with unique, essential quantities to characterize 
galaxy properties; (1) true star formation activity reliably corrected for 
dust extinction, (2) metallicity of inter-stellar medium, and (3) AGN 
contribution. Our target redshift, z ~1.5, is not only the frontier redshift 
for galaxy clusters but is also the key epoch for formation and evolution of 
massive galaxies in clusters as our recent studies show high star forming 
activities even in the cluster cores comparable to other lower density 
environments at z >~ 1.5. At this critical epoch, we will look into a 
correlation between SFR, metallicity and stellar mass (known as the fundamental
 relation for field galaxies) and discuss its environmental dependence for the 
first time to quantify their evolutionary stages. Moreover, we will investigate
 the fraction of AGN-dominated galaxies in and around the clusters to see any 
environmental dependence in AGN activity. Together with star formation 
activity, we will address the co-evolution and feedback of AGN during the 
course of galaxy evolution and cluster assembly.