THE IRON L/K EMISSION-LINE RATIO IN PHOTOIONIZED GASES

摘要

We present models for the emission spectra of photoionized gases in the intermediate energy (0.5-10 keV) X-ray region. We discuss the general properties of iron K and L shell emission features—line strengths and recombination continuum emission—and compare the strengths of these features with iron K shell emission and with the spectral features produced by other elements in the same energy range. We show that there is effectively an upper bound to the L/K ratio, and we compare this with the strengths of the features observed from medium-resolution spectra of X-ray binaries and active galaxies.