Upper panels: the spectra and distribution of maser spots for H₂O, NH₃ (9,6), and CH₃OH 2₂–2₁ transitions detected in the W51e2 region. The meaning of the colorful lines and gray bars in the spectra is similar to that in Figure 2. For maps of maser spots, the gray contours show the 1.3 mm continuum, with the start, step, and end levels to be 0.002, 0.002, and 0.018 Jy beam⁻¹. Lower panels: the spectra and distribution of maser spots for H₂O and NH₃ (9,6) transitions detected in the W51e8 region. The gray contours in maps of maser spots show the 1.3 mm continuum, with the start, step, and end levels to be 0.002, 0.001, and 0.018 Jy beam⁻¹. The black dashed box in the lower-left panel marks the H₂O maser spots belonging to W51e8.