Combined ¹⁴N/¹⁵N ratios in N₂H⁺ in regions defined by Fontani et al. (2020) (red) and in regions defined by our work (blue) overlaid onto N₂H⁺ (1−0) emission from Fontani et al. (2020) (colour scale); red triangles show locations of continuum emission sources in FIR4 asidentified by Neri et al. (in prep.). The wedge on the right indicates the range of flux density (Jy beam⁻¹). The ellipse in the bottom-left corner represents the ALMA synthesised beam.