EIGER. VII. The Evolving Relationship between Galaxies and the Intergalactic Medium in the Final Stages of Reionization

Abstract We present a comprehensive analysis of the relationship between galaxies and the intergalactic medium (IGM) during the late stages of cosmic reionization, based on the complete JWST EIGER dataset. Using deep NIRCam 3.5 μ m slitless spectroscopy, we construct a sample of 948 [O iii ] λ 5008-emitting galaxies with −21.4 ≲ M UV ≲ −17.2 spanning 5.33 < z < 6.97 along six quasar sight lines. We correlate these galaxies with Ly α and Ly β transmission measured from high-resolution quasar spectra across multiple redshift intervals. We find clear redshift evolution in the correlation between galaxy density and transmission: it is suppressed in overdense regions at z < 5.50, while enhanced at 5.70…