Contour plot of ﹩{\chi }^{2}﹩ for a disk-like model with a halo size of ﹩{z}_{{\rm{h}}}=3\,\mathrm{kpc}﹩ and a diffusion coefficient of ﹩{D}_{0}=1.5\times {10}^{28}﹩ cm² s⁻¹. Similar to Figure 2, the red contours correspond to the ⁵¹V/⁵¹Cr fit, the blue contours correspond to the ⁴⁹Ti/⁴⁹V fit, and the dashed purple lines correspond to the combined ﹩{\chi }^{2}﹩ calculation. Note that the discrepancy between the two observations remains the same as in Figure 2.