JADES: The emergence and evolution of Lyα emission and constraints on the IGM neutral fraction

The rest-frame UV recombination emission line Lyα can be powered by ionising photons from young massive stars in star forming galaxies, but its ability to be resonantly scattered by neutral gas complicates its interpretation. For reionization era galaxies, a neutral intergalactic medium (IGM) will scatter Lyα from the line of sight, making Lyα a useful probe of the neutral fraction evolution. Here, we explore Lyα in JWST/NIRSpec spectra from the ongoing JADES programme, which targets hundreds of galaxies in the well-studied GOODS-S and GOODS-N fields. These sources are UV-faint (-20.4< M_ UV<-16.4), and thus represent a poorly-explored class of galaxies. The low spectral resolution (R∼100) spectra of a subset of 84 galaxies in GOODS-S with z_spec>5.6 (as derived with optical lines) are fit with line and continuum models, in order to search for significant line emission. Through exploration of the R100 data, we find evidence for Lyα in 17 sources. This sample allows us to place observational constraints on the fraction of galaxies with Lyα emission in the redshift range 5.6更多