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The Fe XXII I(11.92 A)/I(11.77 A) Density Diagnostic

Christopher W. Mauche·Duane A. Liedahl·Kevin B. Fournier
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Abstract

Using the Livermore X-ray Spectral Synthesizer, which calculates spectral models of highly charged ions based on HULLAC atomic data, we investigate the temperature, density, and photoexcitation dependence of the I(11.92 A)/I(11.77 A) line ratio of Fe XXII. Applied to the Chandra HETG spectrum of the intermediate polar EX Hya, we find that the electron density of its T_e ~ 12 MK plasma is log n_e (cm^-3) = 14.3^{+0.7}_{-0.5}, orders of magnitude greater than that observed in the Sun or other late-type stars.

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Christopher W. Mauche, Duane A. Liedahl, Kevin B. Fournier. 2003-01-31. The Fe XXII I(11.92 A)/I(11.77 A) Density Diagnostic. https://arxiv.org/abs/astro-ph/0301633

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