The damping wing of the Gunn-Peterson absorption and Lyα emitters in the pre-reionization era

We use a numerical simulation of cosmological reionization to estimate the likelihood of detecting Lyalpha-emitting galaxies during the pre-reionization era. We show that it is possible to find galaxies even at z similar to 9 that are barely affected by the damping wing of the Gunn-Peterson absorption from the neutral intergalactic medium outside of their H it regions. The damping wing becomes rapidly more significant at z > 9, but even at z > 10 is it not inconceivable (although quite hard) to see a Lyalpha emission line from a star-forming galaxy.