(Proposal ID) S11B-056

(PI) Okoshi, Katsuya

(Proposal Title)
Faint emissions from heavy absorbers II: NIR imaging spectroscopy

(Abstract)
We propose to carry out a systematic search for reliable detections of the 
star formation activity associated with high-z Damped Ly alpha systems (DLAs) 
with Keck telescope. We are going to use OSIRIS IFU spectroscopy mode whose 
sensitive wavelengths correspond to the redshifted H alpha/[O iii] emission 
lines of targeting DLA absorbers at z > 2. Moreover, high resolution imaging 
with LGS-AO enables us to approach very close to the center of background QSOs 
to detect DLA galaxies at small impact parameter. The combination of large 
ground-base telescope + high-performance LGS-AO + IFU spectroscopy is the most 
promising way to search for faint emissions with small impact parameters. In 
this project, our primary goal is to identify counterpart galaxies from 
targeting DLAs and to further increase the number of direct detections of 
high-z DLA galaxies. We will measure SFR, size, morphology, which can be 
compared with those of Lyman break galaxies (LBGs)/Lyman  alpha emitters 
(LAEs). The sample enables a unique study of the high-z population selected 
homogeneously by neutral gas content, rather than by brightness or color. 
This will remarkably improve the understanding of the relationship between 
DLAs and LBGs/LAEs as well as IGM-galaxy connection in high-z universe.