(Proposal ID) S13A-078

(PI) Okoshi, Katsuya

(Proposal Title)
Survey for Galaxies associated with coincident, multiple HI gas at high-z II

(Abstract)
We propose to carry out a systematic search for reliable detections of star 
formation activity associated with coincident, multiple HI gas in spectra of 
gravitationally lensed quasars at high redshift with Keck telescope. By 
measuring the spatial distributions of HI gas and associated metals, we aim to 
establish a comprehensive picture for understanding how the circumgalactic 
media affect the formation and/or evolution of primordial galaxies.  We are 
going to use the OSIRIS IFU spectroscopy mode whose sensitive wavelengths 
correspond to the redshifted H alpha emission lines of host galaxies at z>2. 
The high resolution imaging with LGS-AO enables us to approach the galaxies 
hosting HI gas at small impact parameter (<1 arcsec) without hampering the 
glare of background quasars. The combination of high-performance LGS-AO + IFU 
spectroscopy + gravitationally lensing is the most promising way to search for 
faint emissions associated with multiple HI gas from small to large impact 
parameters in the circumgalactic medium.