Similar to Fig. B.1 but towards G1.87−SMM 27, 28, 31. The contour levels start at 3σ for SiO, HN¹³C, C₂H, CH₃CN, and ¹³CS. For, HNCO(4_0, 4 − 3_0, 3), HNC, HCN, HCO⁺, HC₃N, and N₂H⁺, the contours start at 9σ, 7σ, 7σ, 4σ, 4σ, and 5σ, respectively. In all cases, the contours go in steps of 3σ. The average 1σ value in T_MB units is ~ 0.63 K km s^-1. The LABOCA 870 μm peak positions are marked by red plus signs. A scale bar indicating the 1 pc projected length is indicated. The SiO and HC₃N emission morphologies resemble each other. HNC and N₂H⁺ also share some common features (e.g. peak close to SMM 28).