Physical conditions enabling Lyα escape at z greater than 10

Determine whether GN-z11 and GS-z13-1-LA possess unique physical conditions that facilitate Lyα escape through a highly neutral intergalactic medium.

Background

The paper compares GN-z11 and GS-z13-1-LA, the only galaxies known at the time with Lyα detections at redshift greater than 10. Such detections are unexpected because the intergalactic medium is expected to be substantially neutral and therefore strongly attenuate Lyα radiation. The authors identify the physical conditions responsible for Lyα transmission—whether unusually large ionized bubbles, broad redshifted line profiles, or specific interstellar and circumgalactic gas geometries—as unresolved.