Spectra of H₂S 1₁₀-1₀₁, H₂³⁴S 1₁₀ -1₀₁, and H₂CS 5₁₄-4₁₄ detected with IRAM for three sources (a, b and c) and HCS⁺ 4-3 and SiO 4-3 lines (d, e and f). All of the observed spectra are aligned to the peak of HC₃N 19-18. In panels (a), (b), and (c), red lines are H₂S 1₁₀-1₀₁, blue lines are H₂³⁴S 1₁₀-1₀₁, and green lines are H₂CS 5₁₄-4₁₄. In (d), (e), and (f), HCS⁺ 4-3 lines are in green and SiO 4-3 lines are red. The black lines in all panels represent HC₃N.