Map of the number of velocity components in the N₂H⁺ (1–0) spectral fits in the G351.77 protocluster. The blue (orange) pixels represent 59% (41%) of the spectra where we adopt a one-velocity-component fit (two-velocity-components fit), see Sect. 3.3. Most of the orange pixels are located in central regions, where we observe the highest S/N and integrated intensity values, similar to the results for G353.41 (Álvarez-Gutiérrez et al. 2024). The blue areas are located preferentially near the edges. The ellipse in the bottom left corner represents the beam size of the N₂H⁺ data.