The parameter contour constrained by the MeerKAT autocorrelation measurement at |$z\approx 0.44$|⁠. We illustrate the correlation between different parameters with 68 per cent (95  per cent) confidence level in grey (light-grey) contours. As a reference, the black solid line is obtained by fixing the parameter |$A_{W_{\rm 50}}$| at different values and calculating the corresponding best |$\Omega _{\rm HI}$|⁠. The firebrick dashed line represents our fiducial model for |$W_{\rm 50}$|⁠, which is obtained from local Universe measurements. The purple star represents the intersection of |$b_{\rm HI}\Omega _{\rm HI}\times 10^3$| embedded in the NUM model and the fiducial |$A_{W_{\rm 50}}$|⁠. The blue line and shadow area denote the estimation and error bar, respectively, derived from MeerKAT x WiggleZ cross-correlation measurements at |$z\approx 0.43$|⁠.