Spectral profiles of emission lines arising from hot molecular gas around W51e8. Left and central panels: spectral profiles of NH₃  for transitions (6, 6), (7, 7), (9, 9), (10, 10), and (13, 13). An offset in flux density is applied to transitions adjacent in energy to better display individual profiles. The lower state energy levels of transitions shown here are ~408−1691 K (see Table 1). The hyperfine satellite lines, separated by ~ ± 24−31 km s^-1 (see Table 3), are detected for the (6, 6), (7, 7), and (9, 9) lines (left panel). A narrower velocity range is plotted in the central panel to show the line profiles of the main hyperfine component of each inversion transition more clearly. Right panel: spectral profile of the J_K = 13₂–13₁ line of CH₃OH (ν_rest = 27.473 GHz. The velocity resolution is 0.4 km s^-1  (all panels) and the vertical dashed line indicates a velocity of 59.9 km s^-1 (central and right panels).