Fig. 2
Opacities from K-shell ionizations for neutral gas and atomic metals as a function of photon energy. All values are for solar abundances. The dotted line gives the opacity of hydrogen alone, dashed is the opacity of hydrogen + helium, and solid is the total opacity of all chemical elements at solar abundances. Values are calculated from Morrison & McCammon (1983). As explained in Sect. 5, the relevant photon energies for Chandra are from 300 eV. Furthermore, for a SSS we do not expect to see any photons above ~3 keV.
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