Abstract:
     In this talk, I will present our survey of circumgalactic medium from z=2--6 through both emission and absorption. Using Keck Cosmic Web Imager, combined with the Subaru/HSC, ALMA and VLA, we studied the detailed kinematics of the circumgalactic medium (CGM). Combined with simulations, our observations suggest that CGM could be heavily metal enriched, and the recycled inflow play a vital role in star foramtion at high-redshift. This could be a reason of the rapid formation of the structure found by recent JWST observations.