(Proposal ID) S14A-114

(PI) Shimakawa Rhythm

(Proposal Title)
 Environmental Dependence in Physical States of Two Proto-Clusters at z>2

(Abstract)
We propose to conduct a deep MOSFIRE spectroscopy of bright H�� emitters in 
the two densest proto-clusters ever known at z>2. The cluster membership of 
our targets are all confirmed with one or more emission lines identified by 
our previous MOIRCS spectroscopy (S13A-039). We now aim to go much deeper with 
the new spectrograph MOSFIRE on Keck which has a much greater sensitivity 
(>5�~) compared to MOIRCS. With a multi-line diagnostics by detecting [OII], 
[OIII] and H�� emission lines for individual galaxies, and combining with 
existing or new H�� and [NII] information, we will fully quantify physical 
states of star-forming galaxies in the proto-clusters for the first time and 
investigate the environmental effects on galaxy formation: (1) True star 
formation rates (SFR) reliably corrected for dust extinction will unveil the 
nature of red H�� emitters, the key population under the influence of 
environmental effects. (2) Gaseous metallicities and ionization parameter will 
characterize the physical states of ISM in the formation phase of cluster 
early-type galaxies, (3) AGN activity in relation to star formation activity 
will scrutinize their co-activation and give clues to the origin of Maggorian 
relation in the cluster environment.