Map toward W43 MM1 of for p-H₂O 1₁₁–0₀₀ (red) and p-HO 1₁₁–0₀₀ (black) in the velocity range [90 km s^-1,110 km s^-1]. The y-axis is from –0.1 to 1.1 for p-H₂O 1₁₁–0₀₀, and p-HO 1₁₁–0₀₀ is scaled by 4. The horizontal green lines define the zero level. The vertical gray lines mark 100 km s^-1. As the signal-to-noise ratio increases for decreasing T_cont, the spectra velocity resolution varies over the map in order to keep it at a minimum value. Hence, with the greatest T_cont, central spectra having a greater number of channels appear plotted darker than those with a lower T_cont. Axis units are offset (″) from MM1.