Effective resolution estimate. Upper left: Haro 11 in UV-continuum, data from Östlin et al. (2009) and Hayes et al. (2009). Data are shown on a square root scale and cut levels set for best detail. Inset in blue is the COS aperture covering the region surrounding knot B in the terminology of Vader et al. (1993). N is up, E is left. Upper right: extracted, throughput-corrected in-aperture image, rotated so horizontal corresponds to the dispersion direction of the spectrograph. Lower panel: collapsed flux profile in the aperture, with the shaded region showing the width of the effective resolution element, which is also given in arc seconds and resolution elements/bins.