spectrum of Obs. 3814 (blue) and 11044 (red) during which Cyg X-1 passed through superior and inferior conjunction, respectively. Residuals to a continuum estimate (a linear fit for 3814, the zero line for 11044) are shown in the bottom panels. The gaps in the spectrum of Obs. 11044 around 3 Å, 6 Å, and 10 Å are due to the filtering of systematic variability from CCD gaps in Chandra’s HETG detector (see Sect. 3.3 and Appendix A).