line of sight distance of the photodissociation regions from R136 with uncertainties of 4pc. Based on their results (Figure 20 in Chevance et al. 2016), the stapler nebula lies less than 20pc away in the line of sight direction from R136, which itself lies at the centre of a sphere of about 6pc in radius. This distance agrees well with the line of sight distance measured from line ratios of ionized lines in optical spectra by Pellegrini et al. (2010). From their Fig.12, we find that the distance of the KN clouds is less than 20pc away in our line of sight from R136.

We also consider that if the CO gas is close to R136, and coincident with the dust, there is likely to be a gradient (reflecting the gradient in the projected $V_{\rm lsr}$) in the dust temperature, and the total fIR luminosity arising from the photodissociation region. Such a gradient is visible in both the dust temperature maps (Guzman 2010), and also in the total fIR luminosity which peaks at KN2, and decreases towards KN3 (see Fig.1 of Chevance of et al. 2016). Therefore, although our observations are unable to resolve the line of sight distances to 