luminous H[ii]{} regions varies as L(H$\beta$)$\propto\sigma^{4.0\pm0.8}$. This result suggests that the most luminous H[ii]{} regions are likely to be virialized, so that information about their masses, and the resultant mass-luminosity relation, could be obtained using the virial theorem (they also claimed a relation between a radius parameter and the square of the velocity dispersion $\sigma$ for H[ii]{} regions, as further evidence for virialization). However, more recent studies, in particular by @Rozas06 suggest that in super-giant H[ii]{} regions, L$\propto\sigma^{2.9\pm0.2}$ may be a more appropriate scaling (the lower exponent arises since H[ii]{} regions with the largest luminosities are generally density-bound, which means that a significant fraction of the ionizing radiation escapes and so does not contribute to the luminosity, making shallower slopes physically possible).

To investigate the scaling relations of star-forming regions, in Fig. \[fig:scaling\] we show the relations between luminosity, size and velocity dispersion of the clumps in our sample compared to Giant Molecular Clouds (GMCs) and H[ii]{} regions in the Milky Way and local galaxies [@Terlevich81; @Arsenault90; @Bordalo11; @Fuentes-Masip00; @Rozas06]. In this plot, we also include the measurements of giant star-forming regions from other high-redshift star-forming galaxies at $z\sim $1 from @Wisnioski11b, the $z\sim $1–2 galaxies from SINS [@Genzel11], and 