Present-day mass function (MF) of the central cluster of N159W. The solid histogram is the MF computed after correction from field stars using the control field; the dotted histogram shows the MF corrected using the CMD analysis (see text for details). Uncertainties in the mass estimates are shown as horizontal lines above the MF, with the vertical lines in each bin indicating the Poisson uncertainties. Fit to the MFs is shown in red, and is consistent with Γ = −1.05 ± 0.2. The 90% completeness limit is shown by the dashed vertical line.