1D and 2D marginal posterior density distributions for the geometric parameters (spherical angles in degrees) conditional on the R19 ST+PST model. In the top right we offer a projected schematic of the angles associated with the crescent region. The coordinates of the crescent region are defined as those of the fiducial point, midway (in angular space) between the convex and concave boundaries of the thickest segment. From left to right, the parameters are: Earth inclination i to pulsar spin axis, ST (single-temperature circular) region center colatitude Θp with respect to spin axis, ST region angular radius ζp; PST (crescent-like) region fiducial-point colatitude θ with respect to spin axis, PST region circular convex (or outer) boundary angular radius ζs; PST region maximum angular width w, the half-angle Δφ of the PST region with respect to the center of the circular convex boundary, and the longitudinal separation Δϕ, with respect to the spin axis, of the center of the ST region from the fiducial point in the crescent. The azimuthal coordinate of the fiducial point is implicit in the separation Δϕ. The half-angle Δφ is that subtended along the convex boundary of the crescent, from the line of symmetry to a terminal point; strictly, the prior density diverges at Δφ = 180° because there is prior support for regions with the topology of a ring, for which the half-angle is defined as 180°. We display the marginal prior density distributions for each parameter as the dashed–dotted functions in the on-diagonal panels. The marginal credible intervals, bounded approximately by the 16% and 84% quantiles in posterior mass, are displayed in the on-diagonal panels as the vertical red shaded bands, and given numerically by CI68%. The highest-density 2D credible regions containing 68%, 95%, and 99.7% of the posterior mass are also rendered in the off-diagonal panels. We give the estimated Kullback–Leibler divergences DKL in bits for each parameter to summarize prior-to-posterior information gain. We refer the reader to R19 for supplementary details about this type of posterior figure.