Dependence of the rotational temperature between the (1, 1) and (2, 2) inversion transition on the NH₃(1, 1) linewidth is shown as contour plot in the top panel and as a scatter plot in the lower panel. The binning of the (1, 1) linewidth in the contour plot is 1 km s^-1 and that of the rotational temperature is 2 K.