Contour plot for m_max. Solid lines show the curves of constant maximum mass in the parameter space of the CSS model. At the beginning and at the end of those lines, the radii corresponding to the maximum mass configurations are also indicated. The vertical dotted line indicates the conformal limit. The blue dashed and dotted lines are curves of constant Λ_1.6, for the two values Λ_1.6 = 250 and 500, which are close to the 68% and 90% confidence interval obtained from the analysis of GW170817 (see Fig. 3).