Radial profiles, in units of HLR, of the surface density of the SFR (Σ_SFR). The curves correspond to the averages obtained for six morphologies of spiral galaxies from González Delgado et al. (2016). The red points shows our extracted Hα data for Malin 1. The blue dashed line indicates the mean level of Σ_SFR in the extended disc of spiral galaxies from Bigiel et al. (2010) with a 1σ level of dispersion (blue shaded region). The error bar in black indicates the typical dispersion among galaxies provided by González Delgado et al. (2016) around each solid curve.