Fits of Gaussian functions to inverted H I absorption spectra of 4C 52.37. The fit paramaters are given in Table A.1. Top: WSRT spectum from Fig. 2 with two Gaussian functions fitted to it (red and yellow dotted lines). The combination of the two fit functions is shown as the black dashed line. The data is colored in gray. Bottom: clipped integrated VLBI spectrum from Fig. 2. Three Gaussian components were fitted to it (colored dotted lines) and their combination is shown as the black dashed line.