The massive X-ray binary Cen X-3 was observed over approximately one quarter of the system’s 2.08 day orbit, beginning before eclipse and ending slightly after eclipse center with the Chandra X-ray Observatory using its High-Energy Transmission Grating Spectrometer. The spectra show K shell emission lines from hydrogen- and helium-like ions of magnesium, silicon, sulfur, and iron as well as a Kα fluorescence emission feature from near-neutral iron. The heliumlike n = 2 → 1 triplet of silicon is fully resolved and the analogous triplet of iron is partially resolved. We measure fluxes, shifts, and widths of the observed emission lines. The helium-like triplet component flux ratios outside of eclipse are consistent with emission from recombination and subsequent cascades (recombination radiation) from a photoionized plasma with temperature ∼100eV. In eclipse, however, the w (resonance) lines of silicon and iron are stronger tha
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