The far-ultraviolet continuum slope as a Lyman Continuum escape estimator at high redshift

ABSTRACT Most of the hydrogen in intergalactic medium (IGM) was rapidly ionized at high redshifts. While observations have established that reionization occurred, observational constraints on high-redshift ionizing emissivity remain elusive. Here, we present a new analysis Low-redshift Lyman Continuum Survey (LzLCS) and literature observations, combined sample 89 star-forming galaxies redshifts near 0.3 with Hubble Space Telescope their continua (or Continuum, LyC). We find strong (6σ significant) inverse correlation between continuum slope 1550 Å (defined as F$_\lambda \propto \lambda ^{\beta ^{1550}_{\rm obs}}$) both LyC escape fraction (fesc, LyC) fesc, times photon production efficiency (ξion). On average, redder slopes smaller than bluer mainly due to higher dust attenuation. More 5 per cent (20 cent) emission escapes $\beta _{\rm obs}^{1550}$ <−2.1 (−2.6). correlations [O iii]/[O ii] flux ratio (at 7.5σ significance), galaxy stellar mass 5.9σ), gas-phase metallicity 4.6σ), observed far-ultraviolet absolute magnitude 3.4σ). Using previous redshift, estimate evolution redshift magnitude. The LzLCS suggest fainter lower dominate budget possibly evolving metal content. Finally, use our × ξion predict during epoch reionization. Our estimated emissivities match IGM emit sufficient photons into exceed recombinations 7–8.