Power-law fits to the bubble size–halo mass relationship (shown in the top left panel of Fig. 8) in the form |$R_{\rm eff}/{\rm cMpc}= R_0 \, (M_{\rm halo}/\text{M}_{\odot })^\alpha$| for each neutral fraction, |$x_{\mathrm{H\, {\small I}}}$| (and corresponding redshift, z) for thesan-1. The power-law slope parameter, α, is plotted in Fig. 9 along with those from lower resolution simulations.