The Fe XI-excited fluorescent cascade in Ne IV

A theoretical spectroscopic investigation of the fluorescent cascade to be expected in nitrogen-like Ne IV, when it is resonantly photoexcited by Fe XI in the solar atmosphere, symbiotic stars, or novae, is described. Primary and secondary cascade intensities are obtained as functions of photoexcitation rate, and expected absolute intensities in the solar atmosphere are derived on the basis of observed Fe XI and Ne EUV emission. Comparisons between the spatially resolved solar situation and spatially unresolved stellar cases of cataclysmic variables, in which these ions have been found to coexist, are made. An interesting possibility of periodic time-dependent fluorescence exists for the binary cataclysmics.