Attenuation-corrected (i.e. intrinsic) ionizing photon production, , as a function of the C III] λ1909 equivalent width (left panel) and the [O III] λλ4959,5007 EW (right). J1154+2443 is shown by the filled blue square; other LyC leakers as filled blue circles. Open symbols show ξ_ion with no attenuation correction for the UV luminosity. Comparison samples are plotted using the same symbols as in Fig. 2. The blue shaded area denotes the range of often assumed as the “standard” value, obtained for constant star formation over a long timescale and subsolar metallicities (cf. Robertson et al. 2013).