Top: Z(X, Y) map or estimated Z young Galactic disk structure, inferred from the Kriging method. The colored dots represent the input data. The spiral arms are the same as in Figure 1, and the linear segment represents the Cepheus spur (see Table 1). Bottom: the Kriging prediction standard deviation σ _Z map (Equation (A3)), allowing for a better assessment of the significance of the detected structures.