Left panel: zero-th order moment map of the NH₃ (1, 1) line obtained with the VLA towards I05345 (red contours). Contours start from the 6% of the maximum (0.039 Jy beam^-1 km s^-1), and are in steps of 10% of the maximum (0.065 Jy beam^-1 km s^-1). The integration velocity interval is  −19.33 and  − 16.24 km s^-1, corresponding to the main group of hyperfine components. Contour levels start from the 3σ rms (~0.0012 Jy beam^-1 km s^-1), and are in steps of 3σ. The grey scale represents the 96 GHz continuum observed with the PdBI (first level is the 3σ rms = 0.004 Jy beam^-1; step = 3σ rms), and the compact 3 millimetre continuum cores detected in Paper II are marked by crosses and labelled as C1-a, C1-b, C2 and C3. The two blue contours correspond to the 3σ level of the integrated emission of N₂D⁺ (3−2) observed with the SMA (Paper I). The arrows identify the emission peaks of the ammonia cores A1 and A2 (this work). The star pinpoints the 3.6 cm continuum peak detected by Molinari et al. (2002). The dashed circle represents the VLA primary beam at ~22 GHz (~114′′). The ellipse in the bottom left corner shows the synthesised beam of the NH₃ (1, 1) image. Right panel: spectra of the NH₃ (1, 1) line towards the continuum cores C1-a, C1-b, C2 and C3, as well as the N₂D⁺ condensations N and S, and the ammonia cores A1 and A2 (see left panel) in synthesised beam temperature units (T_sb). The spectra of C1-a and C1-b have been averaged over the 3σ rms contour level of the 284 GHz emission shown in Fig. 3 of Paper II, because these are resolved in that image only. For C2 and C3, we used the 225 GHz 3σ rms contour level shown in Fig. 1 of Paper I, because the 225 GHz image is less affected by the flux filtering problem.