Rotational diagrams of H₂O calculated using emission lines (left column) and absorption lines (right column), respectively. For emission line diagrams, the logarithm with base 10 of total number of molecules in a level u, , divided by the degeneracy of the level, g_u, is shown as a function of energy of the upper level in Kelvins, E_low. For absorptions lines, the natural logarithm of the column density in a level l, N_l, divided by the degeneracy of the level, g_l, is shown in y-axis. A one-component linear fit is shown with the corresponding value of rotational temperature and error of the fit in brackets. A solid line is used for the cases where at least 10 lines are detected. In the W3 IRS5 emission panel, para-H₂O lines are shown in gray and ortho-H₂O lines in black, respectively.