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Fig. 4


Hn/Hδ line flux ratio versus the quantum number n of the upper level of the transition. The dots show the observed values. Short-dashed, long-dashed and dot-dashed lines plot the ratios for optically thick lines, LTE level populations at three different temperatures, as labeled. The solid line shows the results for LTE, optically thin lines. Predictions of Case B calculations for two different values of the electron density and T = 3000 K are shown by the dotted and the short-long dashed line.

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