No nitrogen fractionation on 600 au scale in the Sun progenitor analogue OMC–2 FIR4. - Fontani, F; Quaia, G; Ceccarelli, C; Colzi, L; López-Sepulcre, A; Favre, C; Kahane, C; Caselli, P; Codella, C; Podio, L; Viti, S (Monthly Notices of the Royal Astronomical Society, 2020)