Determinations of Temperature and Density for Solar-like Stars Using Si XI Soft X-Ray Emission Lines

We study the temperature and density sensitivities of the ratios of Si XI soft X-ray emission lines in the wavelength range of 43-54 Å. The typical temperature of formation of the analyzed lines is around 1.6 MK, which makes this analysis complementary to the analysis of He-like triplets, which are sensitive to hotter plasma. We present theoretical calculations and compare them with ratios obtained from high-resolution X-ray spectra of five solar-like stars: Procyon, α Cen A, α Cen B, ϵ Eri, and Capella. We find that our results are in good agreement with results obtained by other authors through different diagnostics, namely, the analysis of density- and temperature-sensitive He-like triplet lines. We further estimate the coronal pressure and filling factors from Si XI lines in this study.