2022MNRAS.511.5730B

Measuring the escape fraction, f_esc, of ionizing, Lyman continuum (Ly C) radiation is key to our understanding of the process of cosmic reionization. In this paper, we provide a methodology for recovering the posterior probability distribution of the Ly C escape fraction, f_esc^PDF, considering both the observational uncertainties and ensembles of simulated transmission functions through the intergalactic medium (IGM). We present an example of this method applied to a VUDS galaxy at z = 3.64 and find f_esc^PDF = 0.51^+0.33_–0.34 and compare this to the values computed assuming averaged IGM transmission with and without consideration of detection bias along average sightlines yielding f_esc^<T >^ = 1.40^+0.80_–0.42 and f_ esc_^bias = 0.82^+0.33_–0.16. Our results highlight the limitations of methods assuming average, smooth transmission functions. We also present MOSFIRE data for a sample of seven Ly C candidates selected based on photometric redshifts at z > 3.4, but find that all seven have overestimated photometric redshifts by Δz ∼ 0.2 making them unsuitable for Ly C measurements. This results likely due to a bias induced by our selection criteria.