The LyC escape fraction from galaxies, , is strongly boosted by galactic outflows. In the Attenuation-Free Model (AFM) accounting for the properties of z>10 galaxies, radiation-driven outflows develop once the galaxy specific star formation rate, . As the cosmic sSFR increases with redshift, so does , which, when globally averaged, grows from 0.007 to 0.6 in 0z20. We successfully tested the model on specific data sub-samples. Our predictions are consistent with measurements of , and provide a physical explanation for the observed decreasing trend of the mean UV galaxy spectral slope, β, towards high- z.
Ferrara et al. (Mon,) studied this question.