Statistical evidence for the presence of extended Lyα emission in relation to UV continuum and Lyα line luminosities, expressed as probability p₀ of the null hypothesis that a given Lyα profile is consistent with the continuum distribution. Large filled circles: Objects with p₀ < 10^-5 (i.e. very strong evidence for extended Lyα); medium-sized filled circles: Objects with 10^-5 < p₀ < 0.05 (weaker evidence); small open circles: Objects with p₀ > 0.05 (no significant extended Lyα emission detected).