(Proposal ID) S13A-017

(PI) Wang Yiping

(Proposal Title)
Search for galaxy counterparts of Lyman Limit Systems at z>3

(Abstract)
This is a resubmission of the proposal S12A-099 which we have lost due to the 
bad weather. Lyman Limit Systems (LLSs), which are of relatively low ionization
 potential (912A), would succeed MgII as the important candidate tracers of 
"cold" accretion onto galaxies at high-z, and attract considerable attention 
within these two years. We propose high resolution narrow-band imaging at near-
infrared wavelengths with IRCS+LGSAO188 to search for [OII]/[OIII] emissions 
from galaxy counterparts of Lyman Limit Systems at z>3. The proposed deep 
imaging survey will be a crucial first step towards further understanding of 
gas accretion and removal from galaxies over cosmic time, as well as directly 
give evidences and statistics on the prevalence of the alternative galaxy 
formation mode, "cold stream accretion", in the young universe. With the high 
spatial resolution of LGSAO188 and the high performance of IRCS camera on 
Subaru 8.2m telescope, we hope to carry out a narrow-band deep imaging survey 
of 10 high-z QSO fields for S13A, to search for Lyman Limit absorbers at z>3, 
in order to construct a small sample at first.