Radial density profile from our representative LGRB progenitor (model 16TI of Woosley & Heger 2006), which represents a low-metallicity, high-angular momentum, massive star prior to collapse. The low-density power-law tail, visible in the lower-right corner of the figure, has been added by ourselves to the original density profile of the model. It represents a stellar wind with typical Wolf-Rayet mass loss rate Ṁ_w = 10⁻⁵ M_⊙ yr⁻¹ and velocity v_w = 1000 km s⁻¹.