Joint likelihood function over ξ — the parameter of interest — and , b_ν, ref and σ_ref — the selection effect parameters, based on 1473 projected lengths of LoTSS DR2 giants up to z_max = 0.5. We show all two-parameter marginals of the likelihood function, with contours enclosing 30% and 70% of total probability. We mark the maximum likelihood parameters (white circle) and the likelihood mean parameters (white cross). The single-parameter marginals again show the estimated mean, now marked by a vertical line, alongside shaded median-centred 80% credible intervals. The likelihood function is the posterior for a uniform prior. To compare the likelihood function to the posterior actually chosen, see Fig. 16.