An uncontaminated measurement of the escaping Lyman continuum at <i>z</i> ? 3

ABSTRACT Observations of reionization-era analogues at z ? 3 are a powerful tool for constraining reionization. Rest-ultraviolet observations particularly useful, in which both direct and indirect tracers ionizing-photon production escape can be observed. We analyse sample 124 galaxies from the Keck Lyman Continuum Spectroscopic Survey, with sensitive spectroscopic measurements continuum region. present method removing foreground contamination our using high-resolution, multiband Hubble Space Telescope imaging. re-measure global properties cleaned 13 individually detected sources 107 undetected sources, including sample-averaged absolute fraction fesc, abs = 0.06 ± 0.01 ratio ionizing to non-ionizing ultraviolet flux density ?f900/f1500?out 0.040 0.006, corrected attenuation intergalactic circumgalactic media. Based on composite spectra, we also recover strong positive correlation between Ly? equivalent width (W?(Ly$\rm \alpha$)) negative UV luminosity. As previous work, interpret relationship W?(Ly$\rm \alpha$) terms modulation radiation star-forming based covering neutral gas. use \alpha$)-weighted estimate an emissivity as ?LyC ? 5.5 × 1024 erg s?1 Hz?1 Mpc?3. This estimate, evaluated uncontaminated this affirms that contribution background is comparable active galactic nuclei.