KLF, obtaining for each case a reduced $\chi^2$ estimation. In Figures \[fig:nchi1\] and \[fig:nchi2\] we show, for each cluster a contour plot of the reduced $\chi^2$ in a mean age vs age spread plane, indicating the parameter region with the best adjustments.

![The panels show contour maps of the normalized $\chi ^2$ values for the age vs. age spread estimation of clusters DR15-C and DR15-W using pre-main sequence models of the KLF. The most likely values fall within regions with purple and dark blue colors. The white contours indicate 68 and 95 percent confidence limits.The limits of the model grid are indicated by a thin, red line.[]{data-label="fig:nchi1"}](f8a.pdf "fig:"){width="3.0in"} ![The panels show contour maps of the normalized $\chi ^2$ values for the age vs. age spread estimation of clusters DR15-C and DR15-W using pre-main sequence models of the KLF. The most likely values fall within regions with purple and dark blue colors. The white contours indicate 68 and 95 percent confidence limits.The limits of the model grid are indicated by a thin, red line.[]{data-label="fig:nchi1"}](f8b.pdf "fig:"){width="3.0in"}

![Same as in Figure \[fig:nchi1\], but for clusters DR15-SW and DR15-SE[]{data-label="fig:nchi2"}](f9a.pdf "fig:"){width="3.0in"} ![Same as in Figure \[fig:nchi1\], but for clusters DR15-SW and DR15-SE[]{data-label="fig:nchi2"}](f9b.pdf "fig:"){width="3.0in"}

In Table 